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Conversion of 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 converts them to four-digit years using the two-digit year conversion method described below. This conversion method may not convert 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 conversion method and, for date fields where inaccurate date conversions are a possibility, take the following precautions to improve the accuracy of entered dates:

•	Always enter dates with four-digit years.

•	Use the FileMaker Pro 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. For more information, see Defining field validation.

•	On your layouts, always format date fields to display four-digit years. For more information, see Specifying formats for date fields.

Note  This conversion method is used for all forms of two-digit year date entry into FileMaker Pro, not just data entry into fields. For example, date conversion occurs during import of two-digit year dates into FileMaker Pro. For a list of situations where the conversion method is used, see the conversion information below.

Two-digit year date conversion method

FileMaker Pro converts 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 convert to four-digit years.

 

Two-digit year	In 2013, converts to	In 2015, converts to	In 2030, converts to
02	2002	2002	2002
15	2015	2015	2015
42	2042	2042	2042
43	2043	2043	2043
44	1944	2044	2044
45	1945	2045	2045
46	1946	1946	2046
47	1947	1947	2047
50	1950	1950	2050
76	1976	1976	1976
87	1987	1983	1987
95	1995	1995	1995

The following illustration depicts how the conversion method is skewed. It assumes that any two-digit year that you enter is more likely to be in the past than in the future.

This conversion method is used for all forms of two-digit year date input, including:

•	entering and modifying dates in date fields.

•	dates entered in a web-published database that is being accessed via a web browser.

•	dates input or modified via importing. This includes data imported into an existing FileMaker Pro file as well as data converted into a new FileMaker Pro file, but does not include conversion of FileMaker Pro files created in previous versions of FileMaker Pro. See the important note below.

•	dates input or modified via Apple events, ODBC, and JDBC.

•	dates input via drag-and-drop or script commands to a non-active field.

•	dates input as part of a calculation expression in the Specify Calculation dialog box.

•	dates entered for the Auto-Enter Data option in the Options for Field dialog box.

•	dates entered for the Validation In range option in the Options for Field dialog box.

•	dates entered as literal values by scripts.

Important  This two-digit year date conversion method is not used when you convert a FileMaker Pro file from a previous version to the current version of FileMaker Pro. FileMaker assumes that dates in older files constitute legacy data. Therefore, during file conversion, any two-digit year dates that still 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, ideally you should review and correct the data in a previous version of FileMaker Pro prior to converting the file to the current version. For more information about converting files, see Converting files from FileMaker Pro 11 and earlier.

Notes

•	FileMaker recommends that you only enter dates into fields defined with the Date type. Don’t use text or numeric fields to store dates. FileMaker software is not intended to support dates in such fields.

•	FileMaker Pro supports the entry of dates ranging from 1/1/0001 to 12/31/4000.

•	If you need to enter the creation date or modification date for a record, use auto-enter options, which are more accurate and easier than entering the data by hand. For more information, see Defining automatic data entry.

•	In FileMaker Pro 3.0 through 5.5 and FileMaker Pro 6.0v3 and 6.0v4, the processing of dates with two-digit years is different depending on how they are entered. Also, FileMaker Pro 6.0v1 and 6.0v2 have some date handling issues that are corrected in FileMaker Pro 6.0v4.