Addresses [MJ-957], [MJ-955], [MJ-951]
Fixed regression - end date honored
Used dict.get to avoid having to catch exceptions
Check for falsey values instead of catching an exception
used or to conditionally set start and end date for consistency
Merge pull request #762 from DirectEmployers/off-by-one

Addresses [MJ-957], [MJ-955], and [MJ-951]