15 Sep 1997 ISO 8601 describes a large number of date/time formats. This profile defines a few date/time formats, likely to satisfy most requirements. (eg 1997-07-16) Complete date plus hours and minutes: YYYY-MM-DDThh:mmTZD (eg fraction of a second TZD = time zone designator (Z or +hh:mm or -hh:mm).
How and when to use Validation Rules on your fields and tables, in Microsoft Access databases. a-z]*", Any character outside the range A to Z is rejected. Not a future date, Is Null OR <= Date() Use this rule to compare values across different fields, or to delay validation until the last moment before the record is saved.