How to keep a study streak going
The streak goes up when a timer finishes, and the calendar day of that finish is the day that counts.
If you start in the evening and the countdown ends after midnight, the mark lands on the new day. A second finished session on the same date does not add another day. Miss a full calendar day and the current streak goes back to zero. The best mark stays. Those are the rules this timer uses.
A day with very little time
A streak is easier to keep when the block is small enough to finish on a bad day. Twenty-five minutes still counts. On a day with a shift or an exam, that may be all you have, and the day is still marked if the timer reaches zero.
Pick a time you can usually protect. After breakfast is a good one, and so is the hour after you get home. The clock time matters less than noticing, around the same part of the day, that you have not started.
After a missed day
If you miss a day, start again the next time you sit down. The board still shows your best. The current count starts at one, which is where it started the first time. You have finished a session before, so starting again is the same job as day one.
Leave the tab open while you work. If the phone locks, the timer keeps the end time and catches up when you return. The day is taken from that end time, so looking at the screen later does not move the mark onto a later day.
The marks stay in this browser. There is no account. If you clear site data, or you open the site in another browser, you get a fresh board. The old one is still on the first browser unless you removed it.
What to do when the timer ends is in Taking a good break. When you are ready to mark today, the timer is on the home page.