Most twins are born on the same date. A date-only calculator will therefore show an age difference of zero days.
This does not always mean they were born at the same time.
What a date calculator can show
The Age Difference Calculator uses the day, month and year. If both dates are the same, the result is zero years, zero months and zero days.
This answer is correct for a date-level comparison.
When birth times are needed
To find which twin is older by hours or minutes, you need:
- The birth time of the first twin
- The birth time of the second twin
- The date and place of birth
- The time zone, if the places were different
Then subtract the earlier time from the later time.
Example: one twin was born at 10:10 AM and the other at 10:24 AM on the same day. The first twin is older by 14 minutes.
Twins born on different dates
One twin may be born before midnight and the other after midnight. Their dates will be different, even if only a few minutes passed.
A date-only calculator may show one day. For the true short gap, compare the birth times too.
Use the right level of detail
Say “same birth date” when comparing dates. Say “older by 14 minutes” only when reliable birth times are available.
Do not guess the time gap from the dates alone.
Use the Age Difference Calculator