If you say you’re going to call or communicate with someone, complete a task or be somewhere by a certain time, follow through. The other person or people are counting on you. Respect the bond of your word and other people’s time. Don’t let them or yourself down.
Perhaps co-workers need your part of project or information so they can move forward with theirs in a timely manner. Maybe your significant other, family member or friend is waiting for you to let them know when you’re available so you can get together. Perhaps they juggled their schedules to do whatever was agreed upon, but you were late.
I took an acting class in which one topic was professionalism, including punctuality. Yet we’d start late if someone hadn’t bothered to show up on time. I’ve also been at rehearsals that fellow cast members couldn’t make for one reason or another. Their absence makes blocking, dancing and running scenes without them and then catching them up harder for everyone else.
Why do one or two people get to hold up others? As Spock said, the needs of the many outweigh the needs of the few. I believe meetings, rehearsals, gigs, etc. should start when scheduled to respect the time and other commitments of those who did arrive as scheduled.
Some voiceover scripts take longer to be vetted by the client than expected, leaving me with less time to record than expected. The client’s delivery date can’t always be extended, so I may have to work faster.
Of course there can be extenuating circumstances. People might sick, for example. Some blame weather or traffic. That won’t fly with Chicago casting agencies or production companies. They don’t want to hear that traffic was bad or parking was hard to find. They expect talent to leave earlier.
Do your best to do what you say you will.