SysTime.add!"days" missing

[Vladimir Panteleev]

On Monday, 17 March 2014 at 11:11:26 UTC, Spacen Jasset wrote:
> I would like to subtract 60 days from a SysTime, but find that 
> SysTime.add!"days" is not available, unlike Systime.roll!"days" 
> which is available.

You can do this in a simpler way: t -= 60.days;

SysTime.add likely specializes on durations the length of which 
varies depending from their starting point, due to the varying 
number of days in a month or in a year.