Entering dates with two-digit years
FileMaker Pro permits you to enter dates with two-digit years, such as 12/1/99 and 3/2/09. However, these dates are ambiguous because they do not specify the century; entering 5/6/53 could be in the year 1953, 2053, or the 53rd year in any other century.
Important When you enter dates with two-digit years into a date field, FileMaker Pro changes them to four-digit years using the method described below. This method may not change the two-digit year dates that you enter into the century that you expect, which may result in inaccurate date entries.
You should familiarize yourself with this method and, for date fields where inaccurate date changes are a possibility, take the following precautions to improve the accuracy of entered dates:
- Always enter dates with four-digit years.
- Use the field validation option that requires entering four-digit year dates. An error message will appear when an attempted date entry contains a two-digit year. See Defining field validation.
- On layouts, always format date fields to display four-digit years. See Specifying formats for date, time, or timestamp fields.
Note This method is used for all forms of two-digit year date entry, not just data entry into fields. For example, when two-year dates are imported into FileMaker Pro, these changes occur.
Changing two-digit year dates
FileMaker Pro changes two-digit year dates into four-digit year dates based on the year in which the date is entered, always assuming that the four-digit year date should be in either the next 30 years or the preceding 70 years. The following table shows how two-digit year dates entered in three different years will be changed to four-digit years.
|
Two-digit year |
In 2015, |
In 2019, |
In 2030, |
|
02 |
2002 |
2002 |
2002 |
|
19 |
2019 |
2019 |
2019 |
|
42 |
2042 |
2042 |
2042 |
|
43 |
2043 |
2043 |
2043 |
|
44 |
2044 |
2044 |
2044 |
|
45 |
2045 |
2045 |
2045 |
|
46 |
1946 |
2046 |
2046 |
|
47 |
1947 |
2047 |
2047 |
|
50 |
1950 |
1950 |
2050 |
|
76 |
1976 |
1976 |
1976 |
|
87 |
1987 |
1987 |
1987 |
|
95 |
1995 |
1995 |
1995 |
The following illustration depicts how this method is skewed. It assumes that any two-digit year you enter is more likely to be in the past than in the future.
Important This method is not used when you convert a FileMaker Pro file from a previous version to the current version of FileMaker Pro. Dates in older files are assumed to constitute legacy data. Therefore, during file conversion, any two-digit year dates that exist in the old file convert to "19xx" (not the current century, but actually "19xx") in the converted file. If you have any concerns about two-digit year dates in older files, review and correct the data in a previous version of FileMaker Pro before converting the file to the current version. See Converting FileMaker Pro files.
Notes
- Enter dates into fields defined with the date field type only. Don’t use text or numeric fields to store dates. FileMaker software is not intended to support dates in such fields.