Daylight hours in Gustavia
Gustavia gets 13h 12m of daylight on its longest day in June, and 11h 04m on its shortest in December — a difference of 2h 08m across the year.
How fast the days change
Around 17 March, Gustavia gains or loses about 1.0 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 America/St_Barthelemy local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 06:45 | 17:56 | 11h 10m | 12:20 |
| February | 06:38 | 18:12 | 11h 34m | 12:25 |
| March | 06:19 | 18:21 | 12h 02m | 12:20 |
| April | 05:54 | 18:27 | 12h 33m | 12:11 |
| May | 05:38 | 18:37 | 12h 58m | 12:07 |
| June | 05:36 | 18:47 | 13h 12m | 12:11 |
| July | 05:44 | 18:50 | 13h 06m | 12:17 |
| August | 05:53 | 18:37 | 12h 44m | 12:15 |
| September | 05:59 | 18:13 | 12h 14m | 12:06 |
| October | 06:04 | 17:49 | 11h 44m | 11:57 |
| November | 06:17 | 17:34 | 11h 18m | 11:55 |
| December | 06:34 | 17:38 | 11h 04m | 12:06 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 06:15 | 18:22 | 12h 07m |
| June solstice | 21 Jun | 05:37 | 18:49 | 13h 12m |
| September equinox | 22 Sep | 06:00 | 18:07 | 12h 07m |
| December solstice | 21 Dec | 06:37 | 17:41 | 11h 03m |
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.