All date fields were supposed to be inclusive of the start date and exclusive of the end date. That one ended up not being that way was due to my misunderstanding of ruby http://c2.com/cgi/wiki?WhyNumberingShouldStartAtZero <-- this is the reasoning * acochran 's eyes glaze over Anyway, it is a more-or-less standard programming convention to do ranges that way. One advantage that even non-programmers can see is that you don't have to remember what the end date of a month is So, if I want the month of may, I can say May 1 to June 1 rather than having to go, well, 30 days has september.... i see Anyway, it was a conscious decision. So, we should decide what the actual right thing to do is, and then I'll figure out how to do it everywhere. Hopefully, it's what I'm already doing. novalis_: But don't we need all the dates to be inclusive now that we're using both the month date_select (w/o day) and the .datepicker()? For month-long ranges, the idea was that you would select as your start date 5/1/2011 and your end date 6/1/2011. novalis_: well, in this case http://rideconn.dev.openplans.org:3000/reports , there's no day to pick I suppose start and end should set the day to 1 and end should add a month Yeah. * acochran tried but isn't sure how to set a default day. the day is actually already set to 1 (it's in a hidden field) ah, I see you closed the ticket where I commented about this I'll look at how you fixed it and apply anywhere else needed Wait, which ticket? https://openplans.basecamphq.com/projects/5583369-reporting-dispatch-system/todo_items/92074023/comments So, I actually edited the code there. There was some craziness where I was doing date minus 30 days instead of date minus one month which didn't make any sense for a monthly thing if it's exclusive, it should be +1 month, right? I computed the end date first, since in general, we want the previous month's data rather this month's