How can I check when a subnet was created?

Question

There's an unexpected subnet that isn't anywhere in my project I think it was created manually but I can't find when it was created to help descover what it is for and if it's still needed?

Answer 1

On CloudTrail, select Event history, choose Event name from the first drop-down, and CreateSubnet from the second. Then fill in your timeframe.

If you don't have CloudTrail enabled, you will probably be out of luck, as I don't see a timestamp field available via the EC2 API.

References:

https://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-create-a-trail-using-the-console-first-time.html

https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-subnets.html