The duration to expand the interval by.
auto interval1 = PosInfInterval!Date(Date(1996, 1, 2)); auto interval2 = PosInfInterval!Date(Date(1996, 1, 2)); interval1.expand(dur!"days"(2)); assert(interval1 == PosInfInterval!Date(Date(1995, 12, 31))); interval2.expand(dur!"days"(-2)); assert(interval2 == PosInfInterval!Date(Date(1996, 1, 4)));
Expands the interval backwards in time. Effectively, it does begin -= duration.