If you created a Stripe account in Australia, Hong Kong, India, Indonesia, Japan, Malaysia, New Zealand, Singapore and Thailand from 15 March 2022 onwards, your default start of day timezone will be your local country timezone.
If your account was created before 15 March 2022, your default timezone will be UTC unless you have previously changed it.
You can check your start of day in the Payouts section of your Dashboard.
Customized start of day is a feature that controls which payments get grouped together in an automatic payout, by setting your preferred timezone and start time.
For example, if a user in Singapore sets their start of day to “Asia/Singapore” (local timezone) and sets their day to start at 12:00am, then all payments processed from midnight SGT to the next midnight SGT will be attributed to a day, and will be grouped together in an automatic payout.
To learn more about customizing your start of day timezone, visit this page.