Hours of daylight in Vĩnh Long on the 15th of each month, 2026:
Hours of daylight per month in Vĩnh Long. Longest and shortest months highlighted.
Month
Daylight
Sunrise
Sunset
January
11h 35m
06:18
17:53
February
11h 48m
06:17
18:05
March
12h 03m
06:04
18:08
April
12h 21m
05:46
18:07
May
12h 35m
05:36
18:11
June
12h 43m
05:36
18:19
July
12h 40m
05:43
18:23
August
12h 28m
05:48
18:16
September
12h 11m
05:47
17:58
October
11h 55m
05:45
17:40
November
11h 40m
05:52
17:31
December
11h 32m
06:06
17:38
Why the daylight swing runs your mornings
On the shortest days Vĩnh Long gets only about 11h 32m of light. Daylight is the master input to your body clock. Less of it — arriving later and leaving earlier — means your internal timing gets a weaker, later signal, so you drift toward waking in the dark. That is why the same alarm is trivial in June and merciless in December. It is a light problem, not a discipline problem — here is how to use light to fix it, and how to wake up when it is still dark out.
It ranges from about 12h 43m at the longest point of the year (June) down to about 11h 32m at the shortest (December) — a swing of roughly 1h 11m. The chart and table on this page break it down month by month.
When is the shortest day in Vĩnh Long?
Around the winter solstice in December, with roughly 11h 32m of daylight. That is also when mornings are darkest and waking up is hardest.
Does less daylight actually affect sleep and energy?
Yes. Shorter days mean less light to anchor your circadian rhythm, which can flatten your energy, shift your sleep later, and for some people contributes to seasonal low mood. Getting outside early — even briefly — is one of the most effective countermeasures. If low mood is persistent, that is worth raising with a doctor; this is general information, not a diagnosis.
Why is it hardest to get up on the shortest days?
Because your alarm fires while it is still dark, before any daylight has reached your eyes to shut off melatonin and start the cortisol rise that makes you feel awake. Biologically it is still night, so the same wake-up time that is easy in summer feels brutal in winter.
Why people use Captain Wake to wake up on time
Not because it rings louder. Because it removes every way your half-asleep brain talks you back into bed.
1
There is no button to tap
Swiping an alarm away is a reflex you can perform while still asleep. A mission needs your thinking brain switched on — and once it is on, sinking back under is much harder.
2
It survives every trick
Force-quit the app, restart the phone, flip it to silent, turn the volume down. The alarm re-arms and keeps going until the mission is actually done.
3
It gets you physically upright
Photo and barcode missions are anchored to a spot in another room, so the only way to stop the noise is to stand up and walk there. You cannot pre-stage it from bed.
4
It fixes the night, not just the morning
A sleep forecast before bed, bedtime reminders and wake-up streaks — because the 6 AM problem usually starts at 1 AM.
Short days, dark mornings — the alarm that still gets you up.
Captain Wake keeps ringing until you complete a real-world mission. No snooze, no swipe-and-sleep.
