day or night

a cold day in July

The time of occurrence of an event that will never happen.

a day late and a dollar short

Too late and too feeble to achieve the desired effect.

a year and a day

A long time.

as the day is long

Unceasingly; very; thoroughly; to a very high degree.

bad hair day

A day when things seem to be unmanageable or go wrong.

bank night

An event where patrons are enticed to buy entry tickets into some venue, for example a movie theater, with the anticipation that they will be entered into a drawing to win an amount of money if their ticket is drawn and they are on-site at the time of the winning.

banyan day

In British naval tradition, a day of the week when galley kitchens served no meat on board ship.

black day

A day of great disaster, misfortune or unhappiness.