if you don't want to change anything just stick with the old routine, only the clock will be saying it is an hour later than what it is.... this is the easiest thing to do if you are set in a routine as it involves no changing.... i actually found that with the warmer months and more sunshine, i wanted to be outside, or walking, or doing stuff so it was much more convenient having bubs up for the extra hour in the evening, as we would often go for walks etc, down the shop to get an ice cream, just enjoying the summer....

6pm in the summer seems incredibly early for bedtime, but maybe thats just me as i love summer and being outside etc, and have always had my little one there with me and going to bed later during this season...

good luck, it will sort itself out...