[Lazarus] DateDif function needed

[Jürgen Hestermann]

Am 2013-11-18 13:11, schrieb Frederic Da Vitoria:
> First of all, I decided to use a different name. DateDiff comes from Excel, this is Lazarus, we should try to use names consistent with our functions. I chose DatesToAge, but I am not convinced this name is any better to any other name which has been used in this thread. I'll keep it here as this allows to distinguish my routine from others.
>

I still find "CalenderDiff" the best name for this function
because it clearly states that differences are calculated for calender
dates and not for an homogeneous stream of seconds/hours/days.