Wake at 8:00 am
Four bedtimes, each one a whole number of sleep cycles before the alarm, with a quarter of an hour allowed for actually falling asleep.
Go to bed at 12:15 am
5 cycles and 7h 30m asleep: the row nearest eight hours.
| Get into bed | Cycles | Time asleep |
|---|---|---|
| 10:45 pm | 6 cycles | 9h |
| 12:15 am | 5 cycles | 7h 30m |
| 1:45 am | 4 cycles | 6h |
| 3:15 am | 3 cycles | 4h 30m |
7h 30m asleep
The night nearest eight hours, laid on a clock face.
The two assumptions
Move either one and every time above moves with it. The settings follow you around the site.
What an 8:00 am alarm asks of the evening
Eight o'clock gives bedtimes of 10:45 pm, 12:15 am, 1:45 am and 3:15 am. Three of the four rows fall after midnight, the most of any morning alarm in this group, and the six-cycle row is the only bedtime on the evening before.
An 8:00 am alarm is in daylight on every day of the year in New York, Johannesburg, Cape Town and Sydney. London is the exception: from the middle of December to the middle of January the sun there rises after eight, as late as 8:06 am on New Year's Day.
The four-cycle bedtime of 1:45 am falls in the hour the UK skips on the last Sunday of March, and it happens twice on the last Sunday of October. The three-cycle bedtime of 3:15 am comes after every clock change in these five cities, so it is the one row that no change touches. The rows before the change lose an hour in spring and gain one in autumn.
Against a 6:00 am alarm, this page moves every bedtime two hours later. If the two alarms share a week, the weekly tally on the week page adds up what the mix comes to over seven nights.
Further afield, Madrid is the city checked here where an 8:00 am alarm is dark most often: from late September until the clocks go back at the end of October, again from the middle of November to late February, and, in 2026, on the first mornings after they go forward, 29 and 30 March, with sunrise at 8:00 am itself on the 31st. Moscow is dark at 8:00 am from the middle of November to the middle of February, and Berlin from early December to late January. Everywhere else checked here, from Toronto to Tokyo, this alarm is in daylight all year.
The five-cycle bedtime of 12:15 am makes this the first morning alarm in this group where seven and a half hours asleep means going to bed after midnight. In New York the clocks change at 2:00 am, between the 1:45 am and 3:15 am rows, so on the spring-forward night the four-cycle row gives an hour less in bed and the three-cycle row is untouched. In Sydney the clocks go back at 3:00 am on the first Sunday of April, and neither the 1:45 am nor the 3:15 am row falls in the hour that repeats. Moscow's latest sunrise is 9:00 am, at the end of December, Madrid's 8:38 am and Berlin's 8:17 am. Toronto's latest, 7:52 am on 31 October in 2026, the day before its clocks go back, is the latest of the North American cities checked here, so an 8:00 am alarm clears it by eight minutes. In Tokyo the sun is up by 6:52 am even in January, more than an hour before this alarm. Singapore's latest sunrise, 7:17 am in early February, still leaves the alarm three quarters of an hour after it.
Sunrise and sunset: the NOAA solar equations, for each city centre in 2026, to the nearest minute.
Every time on this page comes from two numbers: a cycle of 90 minutes and 15 minutes between getting into bed and being asleep. Neither is a measurement of you. The reference pages say where each one comes from.
A quarter of an hour either way
If the alarm is set to something near but not exactly 8:00 am, the table for it is a page of its own.
The other direction
Already in bed and deciding when to set the alarm? The sleep-now page runs the same sum forwards from the time where you are.