Program or FM to convert number of days into a CalDay format (ddmmyyy)

Question

Hi ABAP friends,
I input calendar day values via a popup calendar from a spreadsheet to BW. So, the values that are populated in BW are the numbers, and not the date.
For ex. when user selects a calendar day for ex. 11-April-2010, the value in excel is stored as 40279 (which is the number of days starting from 01-Jan-1900) and this is the value that gets stored in BW once we save the data.
I'm looking for a function module or method or whatever that converts the above number (40279) into CalDay and writes it to the 0CALDAY infoobject ???
Please help,
Thanks,
Venkat

Answer 1

Thanks Pranaam.
Two things:
1. I cannot find this FM. It says FM doesn't exist. SE37 -->  HR_HK_DIFF_BT_2_DATES
2. My requirement is actually reverse as you explained. I can certainly hard code the starting date: 01011900, but here the input should be the number of days. and I need the date (date2 in your ex.) based on the no. of days entered.
I found another FM which does exist in my BW system. That is: FIMA_DAYS_AND_MONTHS_AND_YEARS
Based on "From" & "To" dates, it outputs the number of days.
But my requirement is:
Based on the starting date (i.e. always 01011900) and number of days, it should give me the "To" date value.