Illustrative example. The dates and amounts below are provided for practice.
A couple wants to record the first few days after a February 28, 2024 start. The next date is February 29, which can be lost in a handwritten count.
Use Relationship Start Date February 28, 2024 and Calculate Until Date March 1, 2024. The output shows two elapsed days and inclusive Day 3.
Check every date once
February 28 is Day 1, February 29 is Day 2, and March 1 is Day 3. The tool compares calendar dates rather than assuming February always ends on the 28th.
The next annual anniversary in this reference view is February 28, 2025. This start is not February 29, so changing the Leap Day Rule does not move it.
A scrapbook entry for March 1 can say “Day 3 together” if the first date counts. A note about the duration should say that two days have elapsed.
Avoid compensating manually for leap years after using the calculator. The date engine has already included February 29. Adding another day by hand would double-count it. The full start and end dates make the result reproducible even when the note is read years later.