Wake at 7:30 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 11:45 pm
5 cycles and 7h 30m asleep: the row nearest eight hours.
| Get into bed | Cycles | Time asleep |
|---|---|---|
| 10:15 pm | 6 cycles | 9h |
| 11:45 pm | 5 cycles | 7h 30m |
| 1:15 am | 4 cycles | 6h |
| 2:45 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 a 7:30 am alarm asks of the evening
Half past seven gives bedtimes of 10:15 pm, 11:45 pm, 1:15 am and 2:45 am. The two late rows each fall inside the hour that one set of countries skips when the clocks go forward.
The late rows are the reason this page is worth reading twice a year. In the UK the clock skips 1:00 am to 1:59 am on the last Sunday of March, so the four-cycle bedtime of 1:15 am does not happen that night. In New York, most of Europe and Sydney the skip is from 2:00 am to 2:59 am, and it is the three-cycle bedtime of 2:45 am that goes missing instead. On the nights the clocks go back, the same bedtimes happen twice.
In New York, Johannesburg and Sydney a 7:30 am alarm is in daylight on every day of the year. In Cape Town it is dark from the middle of May to the middle of August, because the city sits further west in its time zone than Johannesburg and sunrise there reaches 7:52 am. London is dark at 7:30 am from late November to early February, and also for the last week before the clocks go back in October, when sunrise briefly passes half past seven.
Nothing on this page is a bedtime in daylight. The earliest row, 10:15 pm, is after sunset in all five cities all year.
Further afield, the tropical and Gulf cities are light at 7:30 am all year: Singapore, Dubai, Mumbai, Delhi, Hong Kong and Nairobi among them. Madrid has daylight at this hour for only about four months, from the middle of April to late August, plus the fortnight before the clocks go forward in March. Moscow, which has kept the same clock all year since 2014, is dark at 7:30 am from the end of October to late February. Berlin is dark from the middle of November to the middle of February, and Toronto from early December to early February and for the week after the clocks go forward in March. Beijing is dark at 7:30 am only from late December to late January. Auckland is dark at this hour for about a month around its winter solstice, and for the last week before its clocks go back in April. Chicago and Los Angeles are light at 7:30 am all year, although Chicago's latest sunrise, 7:22 am on 31 October in 2026, the day before its clocks go back, comes close. Moscow's sunrise is as late as 9:00 am at the end of December, an hour and a half after this alarm.
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 7:30 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.