The dtsubinv() function

The dtsubinv() function subtracts an interval value from a datetime value. The result is a datetime value.

Syntax

mint dtsubinv(dt, inv, res)
   dtime_t *dt;
   intrvl_t *inv;
   dtime_t *res;
dt
A pointer to an initialized datetime variable.
inv
A pointer to an initialized interval variable.
res
A pointer to a datetime variable to contain the result.

Usage

The dtsubinv() function subtracts the interval value in inv from the datetime value in dt and stores the datetime value in res. This result inherits the qualifier of dt.

The datetime value must include all the fields present in the interval value. When you do not initialize the variables dt and inv, the function might return an unpredictable result.

Return values

0
The subtraction was successful.
<0
An error occurred while performing the subtraction.