Usage notes: also used in the forms the other night and the other week:
I saw him the other night.
the other day
At some point in the recent past. Just the other day I was saying to Bob that I'd love to travel to France.I forgot to tell you that I got a postcard from Mary the other day.
other day, the
One day recently, a short time ago, as in I saw her in the museum the other day. This term originally meant either "the next day" or "the preceding day" (tomorrow or yesterday). In its current meaning it was first recorded in 1421.
the ˌother ˈday, ˈmorning, etc.
only a few days ago: The other evening we went for a drive in the country.I saw Jake the other day while I was shopping.