all day

all day (not comparable)

2. For the period of an entire day, or at least during all the daytime of a day.

   Coordinate term: all night

   We walked all day.

   • 1802, Robert Southey, The Inchcape Rock‎^[1]:

     So thick a haze o’erspreads the sky,
     They cannot see the sun on high:
     The wind hath blown a gale all day;
     At evening it hath died away.

4. (figuratively) Easily; handily; in spades; by far.

   Well, for twenty quid we're having it — it's worth that all day long.

• can do this all day

• as the day is long, daylong, dayslong, for days

• livelong