When to stop, counted backwards
You pick the gap. This turns it into a time, which is the part that is irritating to do in your head at the hour it matters. It is the same arithmetic as everything else here and it is the whole of what this page does.
Screens down at
9:15 pm
A gap of 1 hour before the time in the field above.
That is — from now.
| A gap of | Puts the cutoff at |
|---|---|
| 30 minutes | 9:45 pm |
| 45 minutes | 9:30 pm |
| 1 hour | 9:15 pm |
| an hour and a half | 8:45 pm |
| 2 hours | 8:15 pm |
| 3 hours | 7:15 pm |
What this page will not tell you
It will not tell you how big the gap should be. There is a great deal written about that elsewhere, some of it careful and some of it not, and none of it was written about you. This site counts minutes: it has measured nobody, so it makes no claim about what any particular gap does to any particular person. The number in the slider is yours, and the only thing being added here is the subtraction.
The time in the field is when you get into bed, not when you are asleep. The gap between those two is the drop-off allowance used everywhere else on this site — it has a page of its own — and it sits after this cutoff, not before it.
Where the bedtime comes from
If you do not have one yet, it is the other half of this arithmetic: pick the hour you have to be up and count whole cycles backwards. Every quarter hour has a page, and the single alarm to set at the other end of the evening is on the bedtime alarm page.