Time, mysterious time

Time, mysterious time.
A year, six years
How long is long,
How short is short?
How do some months
Fly fleetingly, carelessly
Whilst it need not hurry;
And others halt,
Wait out. Waiting
In agonising slowness
For days to be marked.
How are these the same
Circles spun, passing
The same numbers
Twenty-four times?
Time, mysterious time
Ticking quietly, unseen
Labouring without rest
Patiently boring holes
One drip,
One drip, at a time.
A constant friend, a foe.
A healer, a murderer.