timestampdiff

Returns an estimated number of intervals of type "expression1" based on the difference between two timestamps. "Expression2" is the result of subtracting two timestamp types and converting the result to CHAR. Valid values of "expression1" are: 1 Fractions of a second; 2 Seconds; 4 Minutes; 8 Hours; 16 Days; 32 Weeks; 64 Months; 128 Quarters; 256 Years.

timestampdiff ( expression1, expression2 )