XL: How to Work With Serial Dates and Julian Dates

ID: Q95078

The information in this article applies to:

Microsoft Excel for Windows, versions 2.x, 3.x, 4.x, 5.x
Microsoft Excel for Windows 95, version 7.0
Microsoft Excel 97 for Windows
Microsoft Excel for the Macintosh, versions 2.x, 3.x, 4.0, 5.0
Microsoft Excel 98 Macintosh Edition

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 in the 20th century.

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

Additional query words: 2.0 2.00 3.0 3.00 4.00 5.0 7.0 8.00 97 XL97 98 XL98


Keywords          : xlformula 
Version           : WINDOWS:2.0,3.0,4.0,5.0,7.0,7.0a,97; MACINTOSH:2.0,3.0,4.0,5.0,98
Platform          : MACINTOSH WINDOWS 
Issue type        :

Last Reviewed: March 31, 1999