Interval.expand

void expand(D)(D duration, Direction dir = Direction.both) if (__traits(compiles, begin + duration)) pure

Expands the interval forwards and/or backwards in time. Effectively, it does begin -= duration and/or end += duration. Whether it expands forwards and/or backwards in time is determined by dir.

Parameters

`duration`	The duration to expand the interval by.
`dir`	The direction in time to expand the interval.

Throws

DateTimeException this interval is empty

or if the resulting interval would be invalid.

Example:

auto interval1 = Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1));
auto interval2 = Interval!Date(Date(1996, 1, 2), Date(2012, 3, 1));

interval1.expand(2);
assert(interval1 == Interval!Date(Date(1994, 1, 2), Date(2014, 3, 1)));

interval2.expand(-2);
assert(interval2 == Interval!Date(Date(1998, 1, 2), Date(2010, 3, 1)));