After checking time and aws configure settings, you may want to go C:\windows\users\, under your username, there is .aws folder, check config and credentials file there, some times there are more than 1 entry which causes conflict.
Delete both the files, and run "aws configure" again, it should fix the issue.
In summary, check below things
1.check the permission of the IAM user and ensure it has administrator access policy attached to it via the group.
2.Check date on local machine, make sure you run aws configure
3. Delete the config & credentials file from the .aws folder and ran aws configure command again