- If both expressions have a Period data type or a derived period, the function returns TRUE if the ending bound of the first expression is equal to the beginning bound of the second expression or the ending bound of the second expression is equal to the beginning bound of the first expression; otherwise, the function returns FALSE.
- If one expression is a Period data type and the other expression is a DateTime expression, the function returns TRUE if the ending bound of the Period expression is equal to the DateTime expression or if the DateTime expression plus one granule is equal to the beginning bound of the Period expression; otherwise, the function returns FALSE.
- If either expression is NULL, the function returns UNKNOWN.