London
See sunrise, sunset and day length for every day of the month. Navigate between months and click any date for details.
The calendar lays out sunrise, sunset and day length for every day of the month, side by side. Where the year chart gives you the shape of the whole year, the calendar is for the specific: what time does the sun come up on the weekend you have an early start, and how much lighter has it actually got since last month?
Compare the first and last day of the month and you get the month's total gain or loss of daylight. That figure varies enormously across the year. In March and September day length shifts by roughly 4 to 5 minutes a day at UK latitudes, which adds up to more than two hours over a month. In June and December the change is close to zero, and a whole month can pass for the sake of a couple of minutes.
Sunrise and sunset do not move by equal amounts either. Through autumn sunset pulls back faster than sunrise pushes later, and through spring it is the other way round. That is why the evenings can feel dark long before the mornings do.
Times are calculated astronomically for the coordinates you have chosen and converted to that location's own timezone. Two cities on the same latitude get the same day length but not the same clock times: London and Plymouth see almost the same number of daylight hours, while the sun rises and sets around 16 minutes later in Plymouth because it sits further west in the same timezone.
Note too that day length at the equinox is not exactly 12 hours but closer to 12 hours and 9 minutes. Sunrise and sunset are measured from the moment the sun's disc touches the horizon, and the atmosphere bends the light, so the sun is visible slightly before it is truly up — and slightly after it has set.
A single day's sunrise time tells you very little. A month of them, laid out together, tells you the two things people actually want to know: which direction the light is moving, and how fast.
Reading down a column, the pattern that emerges depends entirely on the time of year. In March and September the numbers march steadily — three to four minutes a day at British or Danish latitudes, so roughly half an hour a week at each end of the day. In June and December they barely move at all; a fortnight either side of the solstice can pass with under five minutes of change in total. This is the flat top and steep flank of the annual curve, seen close up.
The other thing a month view exposes is that sunrise and sunset do not move symmetrically. You might expect the day to grow equally at both ends, and it does not.
The asymmetry comes from the equation of time — the fact that solar noon itself drifts against clock time across the year, by up to about sixteen minutes in each direction. The day length is set by the sun's geometry, but where that day sits on the clock is shifted by this separate cycle.
Add the two together and the effects can partially cancel at one end of the day and reinforce at the other. In late December this is at its most visible in the northern hemisphere: the earliest sunset occurs around 12 December, more than a week before the solstice, while the latest sunrise does not arrive until early January. For those three weeks the evenings are already drawing out while the mornings are still getting darker — an experience that makes no sense until you know the mechanism.
The same thing happens in mirror image in June, though the amplitude is smaller: the earliest sunrise falls a few days before the solstice and the latest sunset a few days after it. Our page on when it is lightest goes into the equation of time in more detail.
The calendar is not a lookup from a table of major cities — every cell is computed from the coordinates you give it, in the local timezone those coordinates fall in, with any daylight saving transition applied on the correct date. Move a hundred kilometres east and every time in the grid shifts a few minutes earlier; move a hundred kilometres north and the times change asymmetrically, because the day itself is a different length.
Watch for the month in which the clocks change: one row will jump by a full hour. That is not an error in the calculation. It is a reminder that daylight saving time moves the clock, not the sun — the amount of daylight that day is within a couple of minutes of the day before.
The calendar is the close-up view. For the shape of the whole year in one image, use the year chart; to see how two places differ on the same date, the comparison tool; and for the geographical pattern, the daylight map. If you want the definitions behind the numbers — what counts as sunrise, and how accurate it is — those are on the how we calculate the times page.
It depends entirely on the season. In March and September the UK gains or loses more than two hours of daylight over a month, while around June and December the change is down to a few minutes for the whole month.
Because sunrise and sunset are measured from the moment the sun's disc touches the horizon, and because the atmosphere bends the light. Together those add up to about 12 hours and 9 minutes rather than 12 hours.
Day length is set by latitude, while the clock time also depends on longitude within the timezone. London and Plymouth therefore see almost the same number of daylight hours, but the sun rises and sets around 16 minutes later in Plymouth.