timeanddate.com
 

This web site has a number of time and date calculators that are useful for historians and genealogists. (1)

Many older grave markers have the date of death and the number years, months, and days lived. From that, the date calulator (2) will calculate the date of birth.

Reference

o "Timeanddate.com," www.timeanddate.com (Stavanger, Norway: Time and Date AS [AS - "Aksjeselskap"]; accessed 2011 Nov 13).

Notes

1. "Uses for the Date Calculators," www.timeanddate.com/.../calculatoruses.html (Stavanger, Norway: Timeanddate.com; accessed 2011 Nov 13).

2. "Date calculator: Add to or subtract from a date," www.timeanddate.com/...ateadd.html?type=sub (Stavanger, Norway: Timeanddate.com; accessed 2011 Nov 13).