OK. How do they know?

The clocks went forwards on Sunday yet my two almost read the clock when it came time to go out for walkabout and terrorising the local pheasants.  When we are off work, their time is 05.30 and 16.00 (thereabouts). Can any one tell me why they got all busy with themselves at the exact times even though the clocks had moved? Are they picking up our vibes? Also, does anyone find, regardless of how you try to disguise the fact they are spending the weekend away with mum and dad in the caravan, the excitement is unbearable for them? We so try to 'pack' in private (eg one of us takes them out) but clearly they pick up on something.