It's almost four in the morning as I sit here typing away. The hours of a given day are imbued with cultural, overarching, and personal meaning for all of us. 8 PM is prime time. Midnight is the witching hour. The hours, like certain days of the week, certain months of the year, and certain dates in general, become important or otherwise noted for what they mean to us. To illustrate what I mean, it's time to share a poem by Wislawa Szymborska, appropriately titled "Four in the Morning."
The hour from night to day.
The hour from side to side.
The hour for those past thirty.
The hour swept clean to the crowing of cocks.
The hour when earth betrays us.
The hour when wind blows from extinguished stars.
The hour of and-what-if-nothing-remains-after-us.
The hollow hour.
The very pit of all other hours.
No one feels good at four in the morning.
If ants feel good at four in the morning--
Three cheers for the ants. And let five o'clock come
If we're to go on living.
Write a piece that concerns itself with a particular hour of the day. It can be an exact time, or it can generally refer to the hour itself (as when the clock falls on the hour--or for that matter, the quarter and half hours). Make it mean something, even if that something turns out to be nothing at all.