Recording Dates

Dates MUST conform to the IS0 8601 specification. For an annual, the pattern is YYYY. For a monthly, it is YYYY-MM. For something the periodicity of which is less than monthly, the pattern is YYYY-MM-DD. Academic quarters should be recorded using the following as a pattern.

2016-01/2016-03 (for Winter 2016)
2016-04/2016-06 (for Spring 2016)
2016-07/2016-09 (for Summer 2016)
2016-10/2016-12 (for Autumn 2016)

Use the above as a basis for constructing other patterns, e.g.,

1960-07/1960-12 (Summer/Fall 1960)
1972-12/1973-03 (Winter 1972/1973)

For the first we take the beginning of summer and the end of autumn. For the second we record the month the quarter began that term.

Dates recorded using the above as a pattern will be sorted correctly. Alternative display dates (if desired) can be generated from the underlying ISO 8601 specification.

See Null Values for acceptable patterns.