What time is bedtime?

Zach and Leo get bathed at 6.00-6.300ish then have a bedtime story and go to bed, this is usally by 7-7.30ish. zach however has decided to start getting up at random times and waking Leo up or playing with his toys..
We tried putting him to bed later, but that resulted in a screechy whingey toddler by bedtime who refused to sleep. Putting him to bed earlier does the same... We have always had the same bedtime routine and now Freyja gets a bath at the same time as the boys and gets settled for bedtime too.

Thanks ladies. He is so tired in the day that it's definately not too early we've worked out. I just don't know what to do wit him. Our routine is similar to a lot of yours and he's just being a little monkey. 9pm he went to sleep last night

pippa has phases were she's a nightmare to get to bed she has been better since we dropped her afternoon nap though. normally it's upstairs for bath/shower about 6ish but by the time she's bathed dryed in pj, teeth brushed and story read it's about 6.45-7pm. she does mainly sleep through untill about 630ish would like her to sleep in later but she does sleep for 12 hours so cant have everything