Re: RPG date functions vs. Excel date functions

----- Message from "Englander, Douglas"
<Douglas_Englander@xxxxxxxxxxxxx> on Thu, 17 Sep 2015 11:56:52 -0500

To:

"rpg400-l@xxxxxxxxxxxx" <rpg400-l@xxxxxxxxxxxx>

Subject:

RPG date functions vs. Excel date functions


I am reading an excel spreadsheet via RPG (using Scott Klements
routines). There is one cell containing the number 40999, which
excel interprets as March 31, 2012. The 40999 representing the
number of days from January 1, 1900 (January 1, 1900 would be
represented as 1).

If I initialize a base date in RPG (a *ISO date field) to December
31, 1899, and add the excel number to it (converted to days), I am
expecting to get the date that excel is converting 40999 to (i.e. I
would expect RPG to calculate December 31, 1899 + %days(40999) to be
March 31, 2012 also). However, no matter how I do it, RPG calculates
December 31, 1899 + %days(40999) to be April 1, 2012.

Does anyone have any idea as to why the calculations differ by one
day? I trust IBM over Microsoft, and would take the April 1, 2012
date, but I would like to know why the two dates are calculated

Thank you,

Doug