It puzzles me that companies insist on remote workers working to specific timezones. Having everyone work the same hours seems to negate a key advantage of remote workers - ideally while you are sleeping, progress is still being made on your projects by the various remote teams. They should be able to work independently, asynchronously.
I can understand if they are remote support roles, where you want to ensure you always have staff to deal with enquiries. But for most roles, it seems more important that the work gets done, rather than that the entire team are tied to Slack / Skype at exactly the same hours.