Aix Crontab Every 5 Minutes

If you try to use it and crontab complains it is probably not supported. All the 30 does is say to run it every 30 minutes, which is already does due to the 5 every minute interval. How can I run this as a cron job every 30 seconds? A: This can be done, but not with cron alone. , using an asterisk in the 4th field (month) would indicate every month. Add a job to crontab that runs every minute on AIX. I was supposed to have a log generated in my cronjobs in every five minutes. crontab -l d. As mentioned, a command can be run every minute with the crontab time signature of * * * * * (5 stars) followed by the command. As the system administrator you need to review Bob’s cronjobs. crontab -lu bob b. halt instructs the hardware to stop all CPU functions. crontab -e Edit crontab file, or create one if it doesn't already exist. The other task which must execute a script at 00:00 /var/www/html/reset. Cron enables users to schedule jobs (commands or shell scripts) to run automatically at a certain time or date. Title : P5 and pSeries Administration and Support for AIX 5L V5. Crontab (CRON TABle) is a file which contains the schedule of cron entries to be run and at what times they are to be run. gz" -exec rm {} \; This crontab execute every day at 6:05 am for any gz files which are older than 100 days and delete the same file. For example, the package for the PHP version 5 programming language installs a crontab named php5 in /etc/cron. at jobs are sometimes used in the place of crontab's because if the machine is off when the crontab is meant to take place, the job never happens. 1 only), as there are many circumstances when one can get along fine with multiple WPARs within one LPAR. */2 should be every 30 seconds as it would be a minute divided by 2. But how do i make it 5:30 ?. To deactive a paging space immediately in AIX 5. ) Repeat pattern like /2 for every 2 minutes or /10 for every 10 minutes is not supported by all operating systems. Crontab (CRON TABle) is a file which contains the schedule of cron entries to be run and at specified times. Use the following example to create Cron time strings you can use for your site's maintenance. 1 개요 [] how to run cron every N minutes 매 N분마다 크론 수행 크론탭 N분마다 수행 크론 작업 매 N분마다 수행. ** before scheduling this cron please make sure that you tested it on test environment and mentioned correct path for file deletion. Anyway, we can make the lag 5 minutes and run the script every 10, assuming all this copying won't have too much impact (I don't think it will - volumes are not that huge), on a very busy day, there might be a GB of archived redo log, plus not all of it is going to be picked up by every find, just the last 30 mins or so. Cview is not running continuously in the background, it needs about 5 minutes for 200 LPARs to produce its output, so from resource point of view, its used resource is very minimal. 1 and higher includes a set of System V commands. The execution on every minute must start at 00:00. How can I trigger the log files again ? Thanks. Rather than use a cron job I set a watch command up for x amount of seconds and run a script to pull the correct logs, filter them and submit them to an ftp or email output. now they want it to run every 45 minutes is there a sane way to automate this in cron or [SOLVED] cron every 45 minutes Download your favorite Linux distribution at LQ ISO. Moved it into root's cron, but still got it (and appeared to screw-up the other entries in root's crontab. netstat command: crontab -l # m h dom mon dow command */5 * * * * netstat -su >> /tmp/udp_status. # log kernel diagnostic messages every 10 minutes 5. It can easily run a script every minute. Let me know if you have any questions by commenting below or tweeting me @frankperez87. While a crontab is a text file, it is not intended to be directly edited. Usefull Unix/ Linux / AIX commands 1) Few Find commands: */30 for every 30 minutes, etc. Cron is one of the most useful utility that you can find in any Unix-like operating system. We have an entry there running a script checkredo every 5 minutes. 3 򔻐򗗠򙳰 Security SC23-4907-03 AIX 5L Version 5. Now, after initial testing you probably don't want to be notifed every time that your cron job has been executed so you can append the >/dev/null 2>&1 string to the end of the file and thie email notification will not be sent. 000-221 VCE File: IBM. How to kill the process. hi, we had a script that was triggered to run every hour. Remove the comment from the skulker entry of the root crontab to enable operation. Linux crontab examples (every X minutes or hours) | alvinalexander. Thus the above convention can be used for all the other 4 fields. run_scheduler(cadence=1, warp=True): print "Will run jobs every 1 second, counting each second as 1 minute" Frequency Calculation. Any value greater than 5 for sar will give the same output as 5 in this example. It can easily run a script every minute. You create entries for each cron job in this file. As usual, if you have any questions, comments, or your own crontab examples to share, just use the comment form below. You can use this tool to generate the crontab commands easily. crontab -e Edit your crontab file. log Disabling email. sh >/dev/null 2>&1. This process basically works for every AIX level, and has been tested with versions up to AIX 7. It is shorthand for the more verbose POSIX form 5,10,15,20,25,30,35,40,45,50,55,00. Generally, crontab uses a daemon, crond, which runs constantly in the background and checks once a minute to see if any of the scheduled jobs need to be executed. IBM Certification Study Guide - pSeries AIX System Administration Developed specifically for the purpose of preparing for AIX certification Makes an excellent companion to classroom education For AIX professionals. AIX Create Task Scheduler using Crontab March 7, 2018 March 7, 2018 danielniko Leave a comment Problem : I want to run a scheduled bash script every day at 00: 00. This type of cron is useful for doing weekly tasks, like log rotation, etc. Cron then wakes up every minute, examining all stored crontabs, checking each command to see if it should be run in the current minute. Schedule a Background Cron Job For Every 10 Minutes. Learn about its synopsis. $ at now + 5 minutes MMDDhhmmss. Schedule a cron to execute on every Sunday at 5 PM. Any value greater than 5 for sar will give the same output as 5 in this example. Answer: Crontab can be used to schedule a job that runs on certain internal. Contribute to peak6/python-crontab development by creating an account on GitHub. For example, to open crontab file, you need to fire this command: crontab -e. sh every minute. Comments or proposed revisions to this document should be sent via email to the following address: disa. The correct way of specifying a cron job would be to: # runs the date command every other hour at the top of the hour 0 0,2,4,6,8,10,12,14,16,18,20,22 * * * date >> /var/log/date. Uber AIX Commands for the Paranoid; min argument treats its argument as minutes. txt We then indexed /tmp/udp_status. An easy to use editor for crontab schedules. If so then the current trigger should not happen. How do I use crontab to execute script every minute on Linux or Unix-like system? The cron daemon used to execute command or scheduled commands or scripts under Linux or Unix-like system. Add a job to crontab that runs every minute on AIX. crontab -e Edit crontab file, or create one if it doesn’t already exist. com job_timeout = Timeout (in Sekunden) des Jobs, andernfalls gilt die Voreinstellung Die 5 Spalten einer crontab für die Laufzeitkonfiguration bieten eine große Anzahl von. Schedule a Background Cron Job For Every 10 Minutes. I know my problem relates to the crontab not being able to convert the Oracle service name. e every minute of every hour through out the year. Github mirror of python-crontab. run_scheduler(timeout=600): print "Will run jobs every 1 minutes for ten minutes from now()" for result in tab. Obtain the fix for this APAR. The WebSphere Application Server Performance Cookbook covers performance tuning for WebSphere Application Server, although there is also a very strong focus on Java, Operating Systems, and methodology which can be applied to other products and environments. Each line of a crontab file represents a job and consists of CRON. If you want every five minutes, use either: */5 * * * * blah meaning every minute but only every fifth one, or: 0,5,10,15,20,25,30,35,40,45,50,55 * * * * blah for older cron executables that don't understand the */x notation. Handy Unix commands for a DBA Crontab Syntax: To submit a task to run every hour at 15 minutes past the hour on weekdays (days 1-5). 3 TL10 SP2 DVD's from IBM, a Windows host, and access to your NIM server. To run a job every hour, specify an asterisk in the hour field. So if you’re certain that the script won’t last more than 5 seconds, it’s probably better to spawn it in the background. For example, */5 in the minutes field indicates every 5 minutes (see note below about frequencies). As mentioned, a command can be run every minute with the crontab time signature of * * * * * (5 stars) followed by the command. These kprocs have no user interfaces and have been largely undocumented in base documentation. This will be supported on the POWER7 server platform. Then, it goes through each row of the output from show full processlist and checks if a process is Query and it is running over 300 seconds(5 minutes). A crontab file contains instructions to the cron(8) daemon of the general form: "run this command at this time on this date". I need to schedule a cron job that will run in every 2 hours, 7 days in a week. chmod 711 /. R at 23:15 for every day of the year we should add to the crontab file the following line: 15 23 * * * Rscript filePath. I used below entry to run this script every 5 minutes. This is useful when you need to specify a value for one of the two fields Day-of-month or Day-of-week, but not the other. Cron enables users to schedule jobs (commands or shell scripts) to run automatically at a certain time or date. Cron job are used to schedule commands to be executed periodically. txt We then indexed /tmp/udp_status. A system administrator often needs to run a command repeatedly in a certain periods of time. If you try to use it and crontab complains it is probably not supported. It did this every 15 minutes. It's syntactically correct but it will be executed every minute in 4 o'clock everyday:. Ask Question Asked 9 years, 8 months ago. e every minute of every hour through out the year. sh shell script using different intervals. This folder spool/mqueue is showing 112GB space. chmod 711 /home. The cron_d resource directly manages cron. sh You can read more about the crontab syntax and available options here at Wikipedia. [min] Minutes that program should be executed on. Unfortunately, no logs were generated since then. Disable Email 7. Method 2: Use Cron available in Unix/Linux systems. Crontab reduces server administrator work and executes the scheduled job at the given time without fail. 10 and nmon v16b. I want to run a crontab cron job which start at 5:30 AM and runs every 5 mins. By default, the AFS tray icon refreshes every 3 minutes. Javascript Crontab Code Generator. It's pretty rare to have to run a cron job every single minute of every day, especially if there is another way of running the process, such as via an application scheduler. hi, we had a script that was triggered to run every hour. sh it does not appear that it is running every 5 min but it did in the beginning. 0 0 * * 1-5 /usr/sbin. Learn multiple techniques to stop the cron daemon from sending an email for each job that is run on your Linux system and their pros and cons. It will then install your crontab file with the contents of "schedule" and create a new file named after your userid. You can setup commands or scripts, which will repeatedly run at a set time. , crontab -l shows nothing), there's no good way to get it back. 总是记不住crontab的用法,每次用到时,都要到处查,呵呵,写到这里吧,查着方便。 crontab命令 crontab命令用于安装、删除或者列出用于驱动cron后台进程的表格。. To avoid running once per minute a number is needed in the first column, like this: 15 * * * * whatever That will run on the 15th minute after every hour. Sans compter que les changements apportés aux fichiers crontabs des utilisateurs lui sont directement signalés par le programme crontab, alors que cron doit vérifier /etc/crontab toutes les minutes bien que l’utilisation de ce fichier soit fortement déconseillée et qu’il puisse être désactivé [5]. Cron is generally used for running scheduled backups, monitoring disk space, deleting files. The crontab format is minute - hour - day of month - month - day of week followed by the command to run. crontab -e For editing other user's crontab entries: crontab -u username -e This will open a file in VI editor. Schedule a cron job every 10 minutes. On solaris 8 and solaris 9 environments. Then, it goes through each row of the output from show full processlist and checks if a process is Query and it is running over 300 seconds(5 minutes). 5min directory, one for each site. As you can see both tools – rsync and crontab – are extremely simple and lightweight yet extremely powerful and highly configurable. sh every minute. Learn multiple techniques to stop the cron daemon from sending an email for each job that is run on your Linux system and their pros and cons. So to deny a user from executing a cron job, sysadmin might have placed your username in the /etc/cron. job_timeout = timeout (in seconds) of the job The 5 columns for runtime configuration in a crontab file offer a large number of combinations. Description: The crontab utility creates or replaces a user's crontab entry. usage, but only runs on Monday through Thursday every five minutes? I need to show the date and time before each new entry within the file. The cron_d resource directly manages cron. I need to schedule a cron job that will run in every 2 hours, 7 days in a week. What command would you use? Choose one: a. # crontab -e (편집 완료후 "wq" 로 exit, vi 상의 명령어 사용하면 됩니다. The crontab command, found in Unix and Unix-like operating systems, is used to schedule commands to be executed periodically. 04 LTS Step-by-Step June 28, 2015 February 26, 2016 m. Frequently used OS (Linux/Solaris/AIX) Command for DBA March 17, 2015 Prakash As a DBA you need to use frequent OS command or alt least how to query the OS and its hardware. For example, you could schedule a backup of your files every Friday. Run a command every 5 minutes. 1, paging space can be added and removed on the fly. Linux This is a quick, easy, shortcut way to schedule an InfoSphere DataStage job in Linux crontab to take advantage of capabilities within crontab not available in the InfoSphere graphical user interface (GUI). run_scheduler(timeout=600): print "Will run jobs every 1 minutes for ten minutes from now()" for result in tab. I need to run something from CRON every 10 or 15 seconds for a while. Cron is driven by a crontab, a configuration file that holds details of what commands are to be run along with a timetable of when to run them. Each user can have their own crontab, and though these are files in /var, they are not intended to be edited directly. If you don't specify a file, the standard input is used. # crontab -e (편집 완료후 "wq" 로 exit, vi 상의 명령어 사용하면 됩니다. The cron resource should only be used to modify an entry in a crontab file. This brief post looks at how to run a cron command every 15 minutes. if you want to run it at the beginning of hour the minute filed needs to be 0 or any other minutes when you want to run it at a specific minute of the hour. Under normal conditions, this is probably ok, but in my case, a user had created a cron job that spawned every 5 minutes and due to a stale NFS mount, the script hung, and very soon cron stopped scheduling new jobs. However, Sendmail still has its uses. Once logged in, run the following command to open your crontab file. Then 1-5 is Monday being 1 and Friday being 5. Obtain the fix for this APAR. hourly, daily or weekly), use crontab, which has the following options: crontab filename Install filename as your crontab file. Cron configuration on Linux OS used in all unix flavors such as IBM-AIX,HP-UX, Sun Solaris, Schedule a Background Cron Job For Every 10 Minutes. Cron is a time based scheduling service on Linux and Unix computers which allows you to run process at specific times for example once a day, once every hour and so on. Please report any problems to the GitLab issues tracker. # # Author: Miquel van Smoorenburg, # Modified for RHS Linux by Marc Ewing and Donnie Barnes # Modified for TurboLinux by Christian Holtje # # Modified for TurboLinux by Go Taniguchi # # # Default runlevel. Also, don't forget to read our previous crontab article that contains 15 practical examples, and also explains about @monthly, @daily,. /usr/local/bin # less killLongRunningSql. what is the difference between "cron" command and "at" command?. 3 Only) NFS-AFS Translator Edit the file /etc/crontab and set a different restart time. If you don't specify a file, the standard input is used. ) Repeat pattern like /2 for every 2 minutes or /10 for every 10 minutes is not. d have the same syntax as /etc/crontab, and each job runs per its unique timetable and as a particular user. I need to schedule a cron job that will run in every 2 hours, 7 days in a week. Here is how: Edit your cronjob file by running crontab -e command; Add the following line for an every-5-minutes interval. Creation, modification, and removal of a crontab should be done using crontab(1). Each user has their own crontab, and commands in any given crontab will be executed as the user who owns the crontab. Hypothetical Situations. ) Repeat pattern like /2 for every 2 minutes or /10 for every 10 minutes is not supported by all operating systems. to 23:45 hrs. >=20 > Can anyone please help me how to test the crontab is working fine or not? >=20 > Thank in Advance > Prasad. Remember, the exams are hands-on, so it doesn't matter which method you use to achieve the result, so long as the end product is correct. cron examines cron entries once every minute. 6) AIX presents a special challenge, as the "crontab" command strips any blanks lines out of the crontab file used as a source. I want to run a cron job that should run a specific shell script /home/jobs/sync. 2 tl10 sp8 aix 6. how do i achieve this as the controls are rather confusing. POSIX does not define a use for slashes; its rationale (commenting on a BSD extension) notes that the definition is based on System V format but does not exclude. 0, REV=2002. A system administrator can decide which user can run cron jobs and which users cannot. 1 oslevel 6100-07-03-1207 I need to confirm that this cron entry is set properly. It is shorthand for the more verbose POSIX form 5,10,15,20,25,30,35,40,45,50,55,00. crontab -e Edit your crontab file. A script must run one minute before the end of every year. Thus the above convention can be used for all the other 4 fields. A system administrator often needs to run a command repeatedly in a certain periods of time. Each user has their own crontab, and commands in any given crontab will be executed as the user who owns the crontab. The sys crontab entries do the following: The first two crontab entries cause a record to be written to the /var/adm/sa/sadd file every 20 minutes from 8 a. Cron is driven by a crontab, a configuration file that holds details of what commands are to be run along with a timetable of when to run them. batch Runs jobs when the system load level permits. I checked with modes and ownership, it remains the same. This is the AIX forum! What you have suggested works on Linux (more precisely it works with the widely-used Vixie-cron), but not the AIX cron. log /db2/SBX/rpmtool I am unable to see that file for every 5 minutes. It can easily run a script every minute. It is shorthand for the more verbose POSIX form 5,10,15,20,25,30,35,40,45,50,55,00. Topics are described for both SPARC and x86. Also, don't forget to read our previous crontab article that contains 15 practical examples, and also explains about @monthly, @daily,. Now, after initial testing you probably don't want to be notifed every time that your cron job has been executed so you can append the >/dev/null 2>&1 string to the end of the file and thie email notification will not be sent. This is my root (sudo crontab -e) crontab setup: */5 * * * * /etc/test. VERSION 1 some devices that we manage are in europe over really slow links and it takes like 30 minutes I love how every time I. What you basically need is the actual AIX 5. Does anyone know how I can get a job to run every 10 or 15 seconds based on a CRON entry? Thanks, Clark. And on this article Your XML friend XPATH command line xmllint ? Linux by Examples. The alternative is to write a shell script that uses 'sleep 5′ command in it. Take the 2-minute tour × If this is not needed put the following command At the end of the cron job line. Thus, the daemon does not need to be restarted if a crontab file is changed. Cron wakes up every minute and checks schedule tasks in crontable. Each line has five time and date fields, followed by a user name (with optional `:group' and `/login-class' suffixes) if this is the system crontab file, followed by a command. txt We then indexed /tmp/udp_status. # log kernel diagnostic messages every 10 minutes 5. We want our job to run at 5 A. d directory. Based on the value entered for sadc the "valid" values for sar are 1 through 5. The Moodle cron script runs different tasks at differently scheduled intervals. Cron is a time-based job scheduler in Unix-like computer operating systems. When the script is triggered via crontab, the script should check whether a previous instance of it the same script is still running. The cron software utility is a time-based job scheduler in Unix-like operating systems. You can setup commands or scripts, which will. Crontab Environment 6. This is no longer necessary (with AIX 6. Unpack the Plugin archive with the gtar command (or with the gunzip and tar commands): gunzip CGPMcAfee-AIX-PPC. To run a command at 5 am on the 1st January you would at the following command to the crontab file: 0 5 1 1 * command. e You cannot schedule a cron job to run every 5 seconds. Ans: 'crontab' command is used for scheduling job in Unix OS. This command will run every minute of every hour of every day of every week in January. If you want to run your script on 10 minutes interval, can configure like below. Topics are described for both SPARC and x86. Let me know if you have any questions by commenting below or tweeting me @frankperez87. To use emacs as your editor, type "export VISUAL=emacs" before typing this command. To run a program, script or job every hour, select '0' in the minute box, our default, and leave the rest blank. aws events put-rule --schedule-expression "cron(5,35 14 * * ? *)" --name MyRule2 The next example creates a rule that is triggered at 10:15am UTC on the last Friday of each month during the years 2002 to 2005. To submit a cron job, specify the crontab command with the -e flag. 3 Standard Edition 5. crontab -r Remove your crontab file. By using --retry-delay you disable this exponential backoff algorithm. say every 5. job_timeout = timeout (in seconds) of the job The 5 columns for runtime configuration in a crontab file offer a large number of combinations. Cron expressions are powerful, but can be pretty confusing. Linux Server Laravel Framework (วันที่เขียนบทความนี้ผมใช้ Version 5. letterkenny. The other task which must execute a script at 00:00 /var/www/html/reset. This brief post looks at how to run a cron command every 15 minutes. crontab format every hour is simple to have hour field as * which runs every hour as the clock switches to new hour. Download Free 000-221 VCE Exam Dumps. Depending on the application the management command can be called from the Unix crontab as often as required. Gone are the days when just installing the product implies acceptance of the license agreement. The AIX Security Technical Implementation Guide (STIG) is published as a tool to improve the security of Department of Defense (DoD) information systems. Crontab Job To Run Every 15 Minutes >>>CLICK HERE<<< cron is a unix, solaris utility that allows tasks to be automatically run in. Github mirror of python-crontab. Pro-tip! On Unix-like operating systems, you can also easily access cron syntax documentation by typing man 5 crontab in shell. Specifically designed to execute commands at a given time. 1 and above, paging spaces can be removed on-the-fly. That's the cron expression for 5 minutes after the hour, every hour. Learn about its synopsis. Home » Unix » Scheduling Cron & At Jobs The init process in AIX starts the cron daemon, or cron, from the inittab file during the initialization process of the. poweroff sends an ACPI signal which instructs the system to power down. About the cron and at commands Contents of the /var/adm/cron directory More about cron commands Setting up a crontab entry 0481-086 and 0481-079 errors from the cron daemon Listing crontab entries Ensuring cron is working. Crontab The crontab (cron derives from chronos, Greek for time; tab stands for table) command, found in Unix and Unix-like operating systems, is used to schedule commands to be executed periodically. cron, crond. Set a cron to execute/run on every 15 minutes. An alternative to the six field crontab syntax would be the two field option which consists of two fields the date / time and the actual command for example to send an email of everyone who has logged into your Linux server everyday you would use the following Crontab entry:. crontab(1) is the program used to modify user crontab(5) files. Every user in a Unix/Linux system has her own crontab. The 8-17 would be every hour from 8am to 5pm and you already have every 5 minutes. 1) # How To Start Cron Daemon In Solaris 10. To make it every 2 minutes, use */2 in the first entry: */2 * * * * my-script. A cron schedule is a simple text file located under /var/spool/cron/crontabs on Linux systems. The above will schedule the cron job to be run every minute of even hours in the day. The execution on every minute must start at 00:00. So it won't restrict the cron from running just from 0 to 30 minutes and then 5 minutes each in that interval. out and so on. Every job's schedule has a frequency. hi, we had a script that was triggered to run every hour. Crontab : To submit a task every Tuesday (day 2) at 2:45PM To submit a task to run every 15 minutes on weekdays (days 1-5) Unix for the DBA;. This section covers the AIX and Physical Location Code tables for the pSeries 630 Model 6C4 and Model 6E4, as well as the 7311 Model D20 I/O Drawer. Hi folks, we noticed a strange crontab behaviour that's quite critical for us. When you specify */5 in minute field means every 5 minutes. The first field is for Minutes. Description: The crontab utility creates or replaces a user's crontab entry. d to periodically purge unused sessions. Generate a quartz cron expression with an easy to use online interface. Use the following example to create Cron time strings you can use for your site's maintenance. The format of a cron command is very much the V7 standard, with a number of upward-compatible extensions. The alternative is to write a shell script that uses 'sleep 5 ′ command in it. Minute [0,59] Hour [0,23] Day of the month [1,31] Month of the year [1,12]. daily through monday to sunday. Related posts:. Crontab format. An easy to use editor for crontab schedules. Information about all System V commands in AIX can be found in the AIX 5. How do I use crontab to execute script every minute on Linux or Unix-like system? The cron daemon used to execute command or scheduled commands or scripts under Linux or Unix-like system. Welcome to FreeBSD! This handbook covers the installation and day to day use of FreeBSD 12. The WebSphere Application Server Performance Cookbook covers performance tuning for WebSphere Application Server, although there is also a very strong focus on Java, Operating Systems, and methodology which can be applied to other products and environments. Although you could run it manually, it would be much easier if you could do it automatically. Traditional (inherited from Unix) cron format consists of five fields separated by white spaces:. Add a job to crontab that runs every minute on AIX Posted on April 18, 2010 by SoCRaT crontab -e 0-59 * * * * hobba crontab -e: opens a text file (via vi) to add your job 0-59: is to run every minute hobba: is the command to run, it's either a Unix command or a script. # crontab -e (편집 완료후 "wq" 로 exit, vi 상의 명령어 사용하면 됩니다. to 23:45 hrs. */5 * * * * root echo Hello but while. Crontab Run Every 5 Minutes Aix your shel script should conist of three main parts: crontab - execute command every 5 mins rm - removes files find - find files with extension log search online. out and so on. log /db2/SBX/rpmtool I am unable to see that file for every 5 minutes. every 1 minute; every 2 minutes; every even minute; every uneven minute; every 3 minutes; every 4 minutes; every 5 minutes; every five minutes; every 6 minutes; every 10 minutes; every 15 minutes; every fifteen minutes; every ten minutes; every quarter hour; every 20 minutes; every 30 minutes; every hour at 30 minutes; every half hour; every 60.