#339 Calendar getDate With Negative Duration

[Wes Lund]

I'm having problems with negative lags (leads). I'm gathering predecessors and attempting to calculate the appropriate "lag date." So, for example, if I have a F-S link with a 3 day lag, I'd take the predecessors finish, and add 3 days of lag.

To do this, I tried using Calendar.getDate. The problem I have is that getDate fails to take negative durations into account. Am I missing something? Is there a simpler/better way to apply a Duration to a Date? Otherwise, I would think we could modify getDate to work with negative durations?

[Wes Lund]

To clarify, I'm getting negative lags (leads) and cannot get the correct date from a given date and negative duration. The positive duration lags are calculating fine.

[Wes Lund]

1. For negative duration calculations, I found Calendar.getStartDate, which will do just fine. One simply has to multiply the duration by -1.
2. Calendar.getStartDate makes the assumption that if 7 days in a row are non-working, that the calendar is defunct. However, there can be 7+ day non-working day periods (think long Christmas breaks). For me, I changed the 7 day check to 365 days, not sure if you want the modification, but I'll include it.

Think that wraps it up. Excuse my ignorance.

[Jon Iles]

Just tidying up old issues, but to confirm thatthe getDate method in the most recent MPXJ releases should handle both positive and negative values correctly.