The time point to check whether this interval is before it.
std.datetime.date.DateTimeException if this interval is empty.
assert(!Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1)).isBefore( Date(1994, 12, 24))); assert(!Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1)).isBefore( Date(2000, 1, 5))); assert(Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1)).isBefore( Date(2012, 3, 1)));
Whether this interval is before the given time point.