My Birthday Moon
The Moon from that day, here for you now.
Thu, August 21, 2031
Waxing Crescent
A slender beginning of light. This Moon was there at your beginning, too.
Time has passed. The shape of that day’s Moon can still be found.
Phase and illumination use noon in Korea (KST) on the selected date. They do not represent the Moon’s exact position at your birth time and place.
A small record of that day
- Date
- Thu, August 21, 2031
- Sunlit surface
- 8%
- Lunar Date
- Lunar 7/4
Share your first sky with someone close.
Moon Phase on 21 August 2031: Waxing Crescent, 8% Lit
The Moon on August 21, 2031
On August 21, 2031, the Moon will be a waxing crescent, 2.9 days old and 8% illuminated, in the constellation Virgo about 393,433 km (244,468 mi) from Earth. The next Full Moon will follow on September 1, 2031.
- Phase
- Waxing Crescent
- Illumination
- 8%
- Moon age
- 2.9 days since New Moon
- Distance from Earth
- 393,433 km (244,468 mi)
- Constellation
- Virgo
- Previous Full Moon
- August 3, 2031
- Next New Moon
- September 16, 2031
- Next Full Moon
- September 1, 2031
Moon phases around August 21, 2031
| Date | Moon | Lit | Age |
|---|---|---|---|
| 8/18 Mon | New Moon | 0% | 29.6d |
| 8/19 Tue | Waxing Crescent | 1% | 0.9d |
| 8/20 Wed | Waxing Crescent | 4% | 1.9d |
| 8/21 Thu | Waxing Crescent | 8% | 2.9d |
| 8/22 Fri | Waxing Crescent | 15% | 3.9d |
| 8/23 Sat | Waxing Crescent | 23% | 4.9d |
| 8/24 Sun | Waxing Crescent | 32% | 5.9d |
Values are calculated with Astronomy Engine at 12:00 Korea Standard Time (03:00 UTC) on each date; New and Full Moon dates are in UTC. Moon age counts days since the New Moon; distance is centre to centre.
How to find the Moon on your birthday
- Choose your birth year, month and day, then show your Moon.
- Read the phase name and illuminated percentage. A Full Moon appears almost completely lit; a crescent shows a smaller sunlit portion.
- Select “Share this Moon” to create an image card for that date.
Does birth time or location change the result?
This date-only calculator uses Astronomy Engine at noon Korea Standard Time (03:00 UTC) on the selected date. It does not calculate the exact sky at your birth time or birthplace. Near a phase transition, a different time on the same date can give a different phase or illumination.