sleeptimer

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Bedtime calculator

The bedtime calculator opens on "wake up at". Set the time you need to be awake, and the cards count backward so the cycles finish at that alarm.

What time should I go to bed?

The result is the time to get into bed. The fall-asleep minutes are separate from the cycle hours: they move that bedtime, and they stay off the hour line on the card.

Bedtime

A bedtime here is that get-into-bed time for one of the six cycle lengths. Move the wake-up or the fall-asleep setting and the bedtime moves with it. The hours on the card stay the cycle count times 90 minutes.

Counting backward

Sleep length is the cycle count times 90 minutes. The fall-asleep minutes are added to that length, and the total is subtracted from the wake-up. With a 6:30 AM wake-up and the starting 15-minute offset, five cycles (7.5 hours) lands at 10:45 PM. Six cycles (9 hours) lands at 9:15 PM. One cycle (1.5 hours) lands at 4:45 AM.

The clock on the control starts at 11:00 PM, the same default used on the rest of sleeptimer, until you change it or open an address that already has an at time. Switch it to your alarm, then press Calculate. If you already know the bedtime and want the morning cards, switch to "go to bed at" or use the sleep time calculator.

Why does this page open on "wake up at"?

A bedtime question usually starts from the morning that cannot move. "Wake up at" is mode=wake in the page address. "Go to bed at" is mode=bed. A valid mode or at in the address replaces the opening values.

Is the card the moment I have to be asleep?

The card is the time to be in bed. The fall-asleep minutes are already subtracted, using the setting for how long sleep usually takes to start. The page cannot know the minute you actually fall asleep.

What does the address remember?

After Calculate, the address keeps mode and at, such as mode=wake and at=06:30, on this same page. Opening that address again restores the plan. Back clears those two fields.