What are the penalties for being late for work?

If you don't go to work, after ~90 minutes you'll get a call from the boss letting you know that you're missing work. It is ok to not answer the call, or answer the call and still not go.

Sims are paid hourly. The more hours you miss, the less pay you get. I tested this with two sims at level 1 business career. One sim earned $128 ($16 * 8), while the other earned $98 ($16 * ~6).

Work performance does suffer while you are not at work. Work performance also does not accrue while you're not at work.

From a gameplay standpoint, it's probably worth being an hour late if you can enter a favorable mood. Of course, if you could get the mood without being late that would be better.