A meaningless definition of time used in reference when speaking to the past. Most typically 'the other day' would connote to being as far back as a week or maybe two; but has been so grossly overused, and therefore, any meaningful annotation slaughtered, that it clearly can now define ANY period of past-time leaving the many delusional to refer to infinite time as just 'the other day'.
Bro 1: Dude, you totally still have a thing for your ex! Remember, you just got drunk and slept with her like, the other day!!
Bro 2: Nah dude, that was like, 6 months ago at the New Year's party, then she moved out of state & I haven't seen her since. It's June now, bro.