SUMMARY
Many government agencies and contractors require the use of Julian dates
(that is, the number of days from the first of the year and the number of
days until the end of the year as printed on most desktop calendars).
In Microsoft Excel, the following formula converts a serial number date to
a Julian date
=TEXT(Standard_Date,"yy")&TEXT((Standard_Date-
DATEVALUE("1/1/"&TEXT(Standard_Date,"yy"))+1),"000")
where Standard_Date is the defined name given to the cell that contains
the date to be converted. The entire formula must be entered in a single
cell.
Note that the following formulas assume that your dates are within the
range of January 1, 1900 to December 31, 1999.
The following formula converts a Julian date to a standard serial date
in Microsoft Excel:
=DATE(1900+INT(Julian_Date/1000),1,MOD(Julian_Date,1000))
To calculate the number of days that have transpired since January 1 of
the current year, use the following formula:
=INT(((NOW()/365.255)-(YEAR(NOW())-1900))*365.255)
To calculate the number of days left in the current year, use the
following formula:
=(DATE(1+YEAR(NOW()),1,1)-(DATE(YEAR(NOW()),1,1)))-
TRUNC(((NOW()/365.255)-(YEAR(NOW())-1900))*365.255)
The following are examples of Julian dates:
Normal date Julian date
-------------------------
Jan-01-1998 98001
Jan-10-1998 98010