That's one of my pet peeves...when I'm late and others as well. It disrespects others when we're not on time, and it short-changes us because we miss out on something, even if it's only the socializing at the beginning. Socializing is important. It forms and builds relationships.
Being late causes others to stumble, either by creating negative thoughts about us in their minds, or by being disrupted when we enter late. Our late entrance pulls them away from whatever is taking place, even if only for a moment, but then can create additional thoughts about our rudeness, why we chose that moment to enter, why we thought we didn't have to be there when everyone else was, and who knows what else.
Being late places us in a falsely superior position assuming we don't have to abide by the set parameters like everyone else, or thinking the one who set the parameters doesn't matter, or was merely making suggestions, not setting mutually agreed-upon rules.
And on the flip side - we shouldn't judge others when they're late. We have no idea why they're late. They may have encountered some calamity or stopped to help someone in trouble. And once again, judging others places us in a position of thinking we're better than anyone else.
Most of the time I've been late, it's because I "needed" to get that one last thing finished before leaving, but if it was so important, perhaps I should've gotten started earlier. Being on time means being a good judge of time, being a steward of the time we're given, and respecting others, as well as ourselves.
Be on time.
I'm a wife, mom, pastor, human...probably not in that order. I struggle each day to be faithful to God, to my family and to my call as a Christian and all of those previously-mentioned roles. I pray to be positive, kind and thoughtful, but tend to fall short on all counts. I am inspired by sunrises and enjoy taking pictures (mostly my kids, deer in the yard and sunrises). I waste time playing stupid computer games and wishing I'd been better at all of the aforementioned roles. ;-)