Tom,
Nam didn't have a time frame. Months were only divided by pay days. No Sunday thru Saturday. No January thru December. The only thing that we could be sure of was day and night and then some times that was not always true. Days were the ones we flew and the ones we didn't. Nights were the ones we had off and the ones we had guard or flare stand-by.
I was always getting letters asking why I hadn't written in so long. I would always say I wrote but then I couldn't remember if was yesterday last week or last month.