Saving all sentient beings (and a full time job)

The Kwan Um School of Zen has "four great vows" that go like this:

Sentient beings are numberless. I vow to save them all.
Delusions are endless. I vow to cut through them all.
The teachings are infinite. I vow to learn them all.
The Buddha Way is inconceivable. I vow to attain it.

I'd just like to state for the record that I'm down with "saving all sentient beings", but I'd also like to note that it's a little hard to do this while working a 50+ hour work week. I'll give it all I have, but on those nights when I'm really, really tired, I hope it's okay if I don't always try to save all sentient beings, maybe just a few of them. :)