it does alter what you are free and available to do, and the types of activities, if you want to, or are expected to take the child....
Eg my three year old still naps for two hours after lunch (a treat!) and won't sleep anywhere but her bed...so weekend lunches are an issue for some of my single child free friends who want to sleep in until lunchtime and then meet up. We are up with the lark so an early breakfast suits us...my child free friends would rather sleep...and I don't blame them.
Last week another friend suggested meeting at the beach (we live overseas). We love the beach and go every weekend, but we are there from .8-2...this doesn't work for them.
Also a 3 year olds bedtime is much earlier than theirs...we eat out regularly with our daughter in nice restaurants but it's dinner at 5 or 6 and home by 8...this is way too early for my child free friends who always decline.
I combat this by having a nanny and a hands on husband who are good at babysitting and childcare so I get to spend time alone with my friends and travel regularly with them...but day to day things are different.