How To: Copy dates stored in three number fields to one new date field

Summary

This article describes how to copy date information from multiple number fields to a single date field.

Procedure

In the following example, the year, month, and day are in separate number fields; the final format will be YYYYMMDD.

1. Open the table.
2. Select Start Editing from the Table menu.
3. Select Add Field from the Edit menu.
4. In the Field Definition dialog box:
   a. Set Name to an appropriate name, for example 'Date'.
   b. Set Type to Date.
   c. Click OK.
5. Make the new date field active.
6. Select Calculate from the Table menu.
7. Type the following in the expression text box of the Field Calculator dialog box.

   Code:
   Date.make([Year].asstring+":"+[Month].asstring+":"+[Day].asstring,"yyyy:M:dd")

   Where, Year, Month and Day are the names of the numeric fields that contain the appropriate information.

   Note:
   ArcView uses date format characters to identify date and time components. 
   

   You format dates by specifying how the year, month, and day appear. A date value plug is one of the following:

   M	the month as an integer from 1 to 12
   MM	same as 'M', two digits with leading zeros
   MMM	the short form of the month name
   MMMM	the long form of the month name

   d	the day of the month as an integer from 1 to 31
   dd	same as 'd', two digits with leading zeros
   ddd	the short form of the day name
   dddd	the long form of the day name

   y	the year without century
   yy	same as 'y', two digits with leading zeros
   yyy	the year with century, four digits with leading zeros
   yyyy	same as 'yyy'
   yyyyy	the year with century, not restricted to four digits

   c	the century, without a leading zero
   cc	the century, with a leading zero for single digit centuries
   w	week of the year (Week 0 is first week with a Thursday)
   ww	week of the year, two digits with leading zeros
   D	numeric day of the week (Sunday = 1), one digit always
   AD	AD or BC string depending upon the year
   CE	CE or BCE string depending upon the year
   J	Julian Day (days since January 1, 4713 BC)
   j	day of the year
   jj	day of the year, three digits with leading zeros