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