That's up to you, and can depend on factors such as agreed terms. Many of our freelancer send their payment requests on a monthly basis. For example, on the 1st of each month, you send your saved timesheets for the previous month, bundled as a single payment request, to your client.
US Freelancers
Ideally, timesheets should be submitted on a weekly basis, with only one timecard allowed per calendar week.
To track your time daily, use the "Save Progress" button. You can return to your timesheet at any point during the week by selecting "Timesheets" from the left sidebar and clicking into your pending entry.
Once your full week of time is entered, select "Submit Timesheet" to send it for client approval and payment.
Do not click "Submit Timesheet" until all hours for the week have been added, as you will not be able to make additional changes or submit a second timecard for that week.