The interval to create a span together with this interval.
std.datetime.date.DateTimeException if this interval is empty.
assert(Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1)).span( PosInfInterval!Date(Date(1990, 7, 6))) == PosInfInterval!Date(Date(1990, 7 , 6))); assert(Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1)).span( PosInfInterval!Date(Date(2050, 1, 1))) == PosInfInterval!Date(Date(1996, 1 , 2)));
Returns an interval that covers from the earliest time point of two intervals up to (but not including) the latest time point of two intervals.