Feature Request: Allow multiple timezones

[HaaLeo]

Is your feature request related to a problem? Please describe.

We have two development teams. One sitting in Germany (timezone Europe/Berlin) and one sitting in the US (timezone US/Eastern). Both teams work from earliest 7am till latest 6pm. So the period they are working is identical. However the timezone is different.

Describe the feature you'd like

I would like Schedules to support multiple timezones. So I can link one Period (7am - 6pm) to a single schedule but apply it in multiple timezones (Europe/Berlin as well as US/Eastern)

Additional context

N/A

[CrypticCabub]

Hi @HaaLeo

If I am understanding your use case correctly, Instance Scheduler should already support what you are describing.

Under the current design of Instance Scheduler, periods are timezone-agnostic and can be shared by multiple schedules. Timezones can then be defined at the schedule level with a default timezone for the entire deployment that will be used if one is not specified on the schedule itself.

To achieve the behavior you describe, you would create a period for your developer hours of 7am-6pm, and then you would create 2 schedules (developer-hours-germany and developer-hours-us). These schedules would both use the developer-hours period but would define different timezones. You can then tag your instances with whichever schedule corresponds to the timezone that they should operate under

[HaaLeo]

Hi @CrypticCabub thx for your response. I meant it slightly different. We use a single instance for both teams. Therefore, we want either one instance Support multiple schedules or better one schedule to support multiple timezones. I hope that makes it somewhat clear 😅.

[CrypticCabub]

A single instance as in a shared EC2 instance that both teams use or a single deployment of Instance Scheduler?

If the latter, Instance Scheduler allows timezones to be defined per-schedule. The stack defines a default timezone that will be used if a schedule does not provide its own specific timezone within which it should operate. Refer to the "london-working-hours" schedule as an example in our Implementation Guide: https://docs.aws.amazon.com/solutions/latest/instance-scheduler-on-aws/sample-schedule.html

As for 1 schedule supporting multiple timezones, I'm not sure I understand how such a thing would be possible. How would we determine the correct state for an instance?

Suppose a schedule with a period of 14:00-16:00, and 2 timezones: UTC+5, and UTC-5. at 10:00 UTC what state is the schedule in? For one timezone it is 5:00 and for the other it is 15:00. Which time do we use to determine whether we are in our running period of 14:00-16:00?

What about a schedule with multiple periods that all define different instance_types for resizing?

The "correct" way under our current design is that each schedule defines exactly 1 timezone within which it operates (or if no timezone is provided, will fallback to the default timezone). If we need to define office hours as 9am-5pm in local time, we do so with a period, and then we can add that period to as many different schedules as we like with each schedule providing the timezone that is necessary to convert a local time into a schedulable time.

[frogamic]

@CrypticCabub I suspect I know what @HaaLeo wants, because I want the same thing, and I guess it is really a duplicate of #233

Currently I work on a project with a single Aurora cluster that services dev teams across Australia (spanning multiple timezones, with and without daylight saving). I would like to be able to shut this DB down outside working hours since it is only needed for dev environments.

Ideally, I would like to create a single schedule that specifies multiple periods in different timezones like so:

# Excerpt from schedules IaC stack
Resources:
AustralianSchedule:
  Type: 'Custom::ServiceInstanceSchedule'
  Properties:
    ServiceToken: !Ref ServiceInstanceScheduleServiceTokenARN
    Name: australian-business-hours
    Description: Cover core business hours in Australia across AWST and AEST/AEDT
    Timezone: Australia/Melbourne
    Periods:
      - Description: "8:30-5:30, mon-fri Melbourne time"
        # This one uses the schedule's default timezone of Australia/Melbourne time
        # i.e. AEST/AEDT depending on daylight saving.
        BeginTime: "08:30"
        EndTime: '17:30'
        WeekDays: 'Mon-Fri'
      - Description: "8:30-5:30, mon-fri Perth time"
        Timezone: Australia/Perth
        BeginTime: "08:30"
        EndTime: '17:30'
        WeekDays: 'Mon-Fri'

Obviously the same thing could be achieved by just specifying a single period that encompasses both the timezones, but that is less clear, more error prone and weird with daylight savings if the timezones treat it differently.

[CrypticCabub]

Thanks for the clarification. I believe I've seen a similar FR before for timezone-aware periods. To say it back -- the ask is for Instance Scheduler to provide a way to specify timezones on a per-period level and allow a schedule to contain multiple of these timezone-aware periods.

I'll re-open this FR and bring it up with the team for further discussion

[HaaLeo]

@frogamic thx for stepping in. That's essentially what I've meant 😅. Thx for reopening @CrypticCabub 🙏🏼.