SQL provides operators to test how to periods relate to each other. In that context, periods are meant as used by application-time period tables (T181). Such periods cannot contain null values on either side nor can they be zero-length.
The overlaps operator provided by this feature (T502) must not be confused with the overlaps operator provided by feature F053, which uses row-value operands.
T502, “Period predicates” is defined in ISO/IEC 9075-2:2023 as optional feature. It first appeared in the 2011 edition.
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