What is a timesheet?

A timesheet is your time entries gathered into a period — a week or a month — so the total can be read rather than counted up entry by entry.

It shows your own time by default. Where your role allows it, you can look at a team's instead.

"No data for this period" means exactly that: no entries fall in the dates you are looking at, most often because the period selector is on a week you did not work.