AWS Instance Scheduler - Help with Schedule


Hey everyone!

Hopefully an easy one for the more experienced of you.

I'm working on getting AWS Instance Scheduler going to scale up/down one of my instances for a burst of traffic that it receives at the first of every month. I just need some help with the syntax of the periods/schedules, and am looking for a little bit of advice.

This is what I'd like the behavior to be:

  1. Last day of month at 9pm (UTC) -> Scale up to larger instance type.
  2. 2nd day of month at 10am (UTC) -> Scale back down for the rest of the month.
  3. Repeat.

I have a period working that uses monthdays = 1-2 for the first task, but I want it to start a few hours prior. Then for the second I'm using monthdays = 3-F, but again, I'd like to be able to specify the exact time instead of 00:00 UTC, and that's where I'm hitting a wall.

Thank you!

  • Hi, The best option could be to create tags on each EC2 instance you want to upscale and down.

    • Create a lambda function with parameter up and down
    • Lambda will scan all the ec2 with that tab and will stop it -> change instance type
    • Call this Lambda with cloudwatch with the parameter of up and down at your time. Ideally you will be required to add 2 scheduler 1 for scale up and another is for scale down.

    **Don't you think it will create down time when instance will be stop for sometime to change the instance type? I assume it will have backedup instances in LBr to route traffic to heathy instances.

    If you want i can share the code of this..

asked 2 years ago431 views
2 Answers


This should be a simple fix - all you should need to do is add these lines:

  "begintime": {  
    "S": "21:00"  
  "endtime": {  
    "S": "10:00"  
  "timezone": {  
    "S": "UTC"  

which will ensure the upscaling function will execute at 9pm UTC and stop the next day at 10am UTC. You can then edit your downscaling function to execute at your desired time until the next upscale time.


answered 6 months ago
answered 2 years ago

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