January 10, 2008
Being a nerd, I have a salary history spreadsheet that contains every pay increase, every promotional raise, and every new job I've had in over the past twenty-five years. As much as possible these events are tied to the actual dates, therefore I can calculate how much I made at each salary.
The limitations of the Excel DAY() function come into play here, as it treats each year as twelve 30-day units, for a total of 360 days. Five missing days twenty five times is only 125 days out of 9125, or 1.36%. and acceptable margin of error.
Today I had the pleasure of entering this year's salary increase, and in seeing a new lifetime earnings total.