4.0
- PHP 7.3 is now the minimum required version.
0,null,false,trueare now supported values as in that they result inDuration::none()(PT0S).- An
InvalidDurationerror will be thrown if a value is given without a unit or if the given value cannot be parsed. toIntervalSpec()did more than it needed to do. Instead of formatting the current value the spec itself is now returned.