There's never a right time
I'm about to go on holiday (yay me!), but have you ever worried beforehand because there's not enough time to complete everything you need to get done before you go?
Lets face it:-
There's rarely enough time to do everything in the average week when you've got a full week; without meetings or interruptions -let alone when you've got a deadline like a holiday!
So relax; make the deadline work for you. Use it as a way to get things done with a little more focus and clarity. Identify what needs to be done before you go and what can wait for your return and then prioritise what needs to be done. If you get it all done -great. If not, I suspect that it can wait for your return so enjoy yourself knowing that you'll get stuck in on your return.
Down time is important for everyone, if your clients worry about you going away, you can reassure them that when you get back you'll be raring to go.
Shameless plug - if you are thinking about going on holiday -but worried about supporting your clients, you should check out Crisis Cover. Crisis Cover allows you to store important information such as usernames and passwords and give on-demand (and audited) access to anyone supporting your clients in your absence.