How yahrzeit dates work: Hebrew dates, civil dates, and family practice
A yahrzeit is remembered by a Hebrew date, while the civil date shifts from year to year. Keeping both, with a source and a note about family practice, prevents small uncertainties from becoming permanent confusion.
Begin with the original date
Record what the family actually knows: the name, date of passing, place, and source. If you have only a civil date, keep it exactly as received and mark that the Hebrew conversion still needs confirmation.
Why the civil date moves
The Hebrew calendar is lunar-solar, so the corresponding civil date changes each year. A calendar that stores the Hebrew source date can calculate future civil reminders while leaving the original record intact.
Keep practice separate from calculation
Families may observe dates differently in unusual calendar cases. Record your family’s note and ask a rabbi for religious guidance when needed; software can organize information, not issue a ruling.