In a previous post, I described how to get the date for a day in the past. This method unfortunately doesn’t work on FreeBSD hosts, since FreeBSD doesn’t come with the GNU date utility. As an alternative to GNU date, you can pass a time value to the date utilities “-v” option to print a date in the past:
Mon Jan 1 13:02:57 EST 2007
I think I prefer the GNU date syntax, but this seems to work pretty well.