Period reference

Periods contain conditions that allow you to set the specific hours, days, and months an instance will run. A period can contain multiple conditions, but all conditions must be true for the Instance Scheduler on AWS to apply the appropriate start or stop action.

Start and stop times

The begintime and endtime fields define when the Instance Scheduler on AWS will start and stop instances. If you specify a start time only, the instance must be stopped manually. Note that if you specify a value in the weekdays field, the solution uses that value to determine when to stop the instance. For example, if you specify a begintime of 9 AM with no endtime and a weekdays value of Monday through Friday, the instance will be stopped at 11:59 PM on Friday unless you have scheduled an adjacent period.

Similarly, if you only specify a stop time, the instance must be started manually. If you don't specify either time, this solution uses the days of the week, days of the month, or months rules to start and stop instances at the beginning/end of each day as appropriate.

The begintime and endtime values for your period must be in the time zone specified in the schedule. If you do not specify a time zone in the schedule, the solution will use the time zone specified when you launch the solution.

If your schedule contains multiple periods, we recommend that you always specify both a begintime and endtime in your periods.

If you start an instance before the specified start time, the instance will run until the end of the running period. For example, a user might define a period that starts an instance daily at 9 AM and stops that instance at 5 PM.

9-5 scheduled start and stop

If you manually start that instance at 5 AM, the solution will stop the instance at 5 PM. If you use the retain running field, the solution will not stop the instance at 5 PM.

5 AM scheduled stop

If you stop an instance before the specified stop time, the instance will not run until the beginning of the next running period. Continuing from the previous example, if the user stops the instance at 1 PM on Wednesday, the solution will not start the instance until 9 AM on Thursday.

5 PM scheduled stop

Adjacent periods

The solution will not stop running instances if the schedule contains two adjacent running periods. For example, if you have a schedule with one period with an endtime of 11:59 PM and another period with a begintime of midnight the following day, the solution will not stop running instances, if there are no weekdays, monthdays,or months rules that stop the instances.

To implement a schedule that runs instances from 9 AM Monday to 5 PM Friday, the solution requires three periods. The first period runs applicable instances from 9 AM to 11:59 PM Monday. The second period runs the instances from midnight Tuesday to 11:59 PM Thursday. The third period runs the instances from midnight Friday to 5 PM Friday. For more information, refer to Sample schedule.

Days of the week

The weekdays field defines which days during the week an instance will run. You can specify a list of days, a range of days, the n^th occurrence of that day in a month, or the last occurrence of that day in a month. The solution supports abbreviated day names (Mon) and numbers (0).

Days of the month

The monthdays, field defines which days during the month an instance will run. You can specify a list of days, a range of days, every n^th day of the month, the last day of the month, or the nearest weekday to a specific date.

Months

The months field defines which months an instance will run. You can specify a list of months, a range of months, or every n^th month. The solution supports abbreviated month names (Jan) and numbers (1).

Period definitions

The Instance Scheduler on AWS configuration table in Amazon DynamoDB contains period definitions. A period definition can contain the following fields. Note that some fields support Cron non-standard characters.

Important

You must specify at least one of the following items: begintime, endtime, weekdays, months, or monthdays.

Field	Description
begintime	The time, in HH:MM format, that the instance will start.
description	An optional description of the period.
endtime	The time, in HH:MM format, that the instance will stop.
months	Enter a comma-delimited list of months, or a hyphenated range of months, during which the instance will run. For example, enter jan, feb, mar or 1, 2, 3 to run an instance during those months. Or, you can enter jan-mar or 1-3. You can also schedule an instance to run every nth month or every nth month in a range. For example, enter Jan/3 or 1/3 to run an instance every third month starting in January. Enter Jan-Jul/2 to run every other month from January to July.
monthdays	Enter a comma-delimited list of days of the month, or a hyphenated range of days, during which the instance will run. For example, enter 1, 2, 3 or 1-3 to run an instance during the first three days of the month. You can also enter multiple ranges. For example, enter 1-3, 7-9to run an instance from the 1st to the 3rd and the 7th through the 9th. You can also schedule an instance to run every nth day of the month or every nth day of the month in a range. For example, enter 1/7 to run an instance every seventh day starting on the 1st. Enter 1-15/2 to run an instance every other day from the 1st to the 15th. Enter L to run an instance on the last day of the month. Enter a date and W to run an instance on the nearest weekday to the specified date. For example, enter 15W to run an instance on the nearest weekday to the 15th.
name	The name used to identify the period. This name must be unique.
weekdays	Enter a comma-delimited list of days of the week, or a range of days of the week, during which the instance will run. For example, enter 0, 1, 2 or 0-2 to run an instance Monday through Wednesday. You can also enter multiple ranges. For example, enter 0-2, 4-6 to run an instance every day except Thursday. You can also schedule an instance to run every nth occurrence of a weekday in the month. For example, enter Mon#1 or 0#1 to run an instance the first Monday of the month. Enter a day and L to run an instance on the last occurrence of that weekday in the month. For example, enter friL or 4L to run an instance on the last Friday of the month.

When a period contains multiple conditions, note that all conditions must be true for Instance Scheduler on AWS to apply the appropriate action. For example, a period that contains a weekdays field with a value of Mon#1 and a months field with a value of Jan/3 will apply the action on the first Monday of the quarter.

Automated tagging

The Instance Scheduler on AWS can automatically add tags to all instances it starts or stops. You can specify a list of tag names or tagname=tagvalue pairs in the Started tags and Stopped tags parameters. The solution also includes macros that allow you to add variable information to the tags:

• {scheduler}: The name of the scheduler stack

• {year}: The year (four digits)

• {month}: The month (two digits)

• {day}: The day (two digits)

• {hour}: The hour (two digits, 24-hour format)

• {minute}: The minute (two digits)

• {timeszone}: The time zone

The following table gives examples of different inputs and the resulting tags.

Example parameter input	Instance Scheduler tag
ScheduleMessage=Started by scheduler {scheduler}	ScheduleMessage=Started by scheduler MyScheduler
ScheduleMessage=Started on {year}/{month}/{day}	ScheduleMessage=Started on 2017/07/06
ScheduleMessage=Started on {year}/{month}/{day} at {hour}:{minute}	ScheduleMessage=Started on 2017/07/06 at 09:00
ScheduleMessage=Started on {year}/{month}/{day} at {hour}:{minute} {timezone}	ScheduleMessage=Started on 2017/07/06 at 09:00 UTC

When you use the Started tags parameter, the tags are automatically deleted when the scheduler stops the instance. When you use the Stopped tags parameter, the tags are automatically deleted when the instance is started.