When to arrive at reception

Typically cocktail hour is an hour long and it's for you to spend time taking pictures. So when you arrive really depends on when you want to do pictures and how long they take. I don't think there is a set rule for this, it's just whatever works for you!

We didn't do a cocktail hour, we just opened the bar and buffet as soon as people started arriving at the reception. We arrived 30mins into it after photos and did a welcome toast

We're doing our photos ahead of time so we're attending our entire cocktail hour. We might greet people as they enter. I don't want to miss anything!

Basically, a cocktail hour is something to host and entertain your guests while you and your new spouse and wedding party take pictures. After the ceremony, the guests usually go to the reception location where the cocktail hour should start. After a while, everyone sits down and the newlyweds make a grand entrance, etc. Ask your photographer how long he or she thinks pictures will take, and then plan on arriving at the end of cocktail hour. Cocktail hour can be shorter than an hour, but I would not go over it because your guests will end up bored and wondering where the couple is.