Daylight hours in Downtown
Downtown gets 12h 32m of daylight on its longest day in December, and 11h 42m on its shortest in June — a difference of 0h 50m across the year.
How fast the days change
Around 12 March, Downtown gains or loses about 0.4 minutes of daylight every day.
Barely perceptible — near the equator the length of the day hardly changes at all, and the seasons announce themselves through rain and heat instead.
Sunrise and sunset by month
On the 15th of each month, in Indian/Chagos local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 07:04 | 19:34 | 12h 30m | 13:19 |
| February | 07:14 | 19:34 | 12h 20m | 13:24 |
| March | 07:15 | 19:23 | 12h 09m | 13:19 |
| April | 07:12 | 19:08 | 11h 57m | 13:10 |
| May | 07:13 | 19:00 | 11h 47m | 13:06 |
| June | 07:19 | 19:02 | 11h 42m | 13:10 |
| July | 07:24 | 19:08 | 11h 44m | 13:16 |
| August | 07:18 | 19:11 | 11h 52m | 13:15 |
| September | 07:03 | 19:07 | 12h 04m | 13:05 |
| October | 06:48 | 19:04 | 12h 16m | 12:56 |
| November | 06:41 | 19:08 | 12h 27m | 12:55 |
| December | 06:49 | 19:21 | 12h 32m | 13:05 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 07:14 | 19:21 | 12h 07m |
| June solstice | 21 Jun | 07:21 | 19:03 | 11h 42m |
| September equinox | 22 Sep | 07:00 | 19:06 | 12h 06m |
| December solstice | 21 Dec | 06:52 | 19:24 | 12h 33m |
The equinoxes give almost exactly twelve hours of daylight everywhere on earth — "almost" because sunrise is defined by the sun's upper edge rather than its centre, and the atmosphere bends its light over the horizon before it has really arrived. Both lengthen the day by a few minutes.
Assumptions
- Sea-level horizon. Hills, mountains and buildings all delay sunrise and bring sunset forward, sometimes by a lot in a valley.
- Standard refraction. Sunrise is taken at −0.833°, allowing for the sun's disc and average atmospheric bending. Unusual air conditions shift it by a minute or two.
- Local clock time, with daylight saving applied from the IANA timezone database.