LastWeekOfMonth DateOffset

[cancan101]

Create a DateOffset that represents the a weekday in last week of the month, such as "the last Tuesday of each month"

Currently there is a WeekOfMonth DateOffset but that class only takes week : {0, 1, 2, 3, ...}. What we actually want is week=-1

I will submit a PR.

[jreback]

I added a 'Frequency' label to tag some of these issues

[cancan101]

@jreback I have a PR in progress for this. It's part of #4511

[patricktokeeffe]

I'm curious why this was implemented as a new class instead of extending the range for WeekOfMonth into the negative range. It seems valid enough to say "the second to last Tuesday of each month" or week=-2.

[cancan101]

I don't think there is a good reason. I would not be averse to just merging that functionality into WeekOfMonth

[jreback]

closed by #5004