Day is dead, and let us sleep

DAY is dead, and let us sleep, 
Sleep a while or sleep for aye,
'Twere the best if we unknew
While to-morrow dawned and grew;
It may bring us time to weep: 
We were glad to-day.
Joy a little while is won,
Joy is ending while begun;
Then the setting of the sun.
  Afterwards is long to rue.