I work full time and have 7 yr old DTDs. It's fine. I drop them at their school breakfast club at 8, get to school for 8.15 (am lucky to live v close to where I teach) and pick them up from after school club, depending on what day it is, by 5 at the latest. They have activities on Wednesdays and Thursdays, so I get them earlier on those days. I always pick them up from the playground on Fridays - again, very lucky because my school finishes at 3 and theirs is 3.15.
I work hard during the day, and whilst I will go to the staffroom at breaktime, I rarely do at lunchtime. I run school activities Tuesday, Wednesday & Thursday til 4 and have to be strict about getting out straight away afterwards.
I work most evenings, and most Sunday afternoon/evenings. I have a very understanding DH.
I make sure that I have time for myself (I'm in a choir - one evening each week is for ME and I am not going to give that up!) which keeps me sane.
Holidays are great, though I still use holiday clubs when I need to. This holiday, the DTDs have had a week with my parents and a few days with my sister so that I could be in school for A Level/GCSE results and get some work done.
You just have to be kind to yourself. It's manageable.