My dog is happiest when we follow a set routine - short walks in the morning before I go to work and again when I come home at lunch; long walk when I get home, which is at the same time every day.  Weekends are indicated by the donning of "adventure pants" (jeans), and he wags his tail happily because he knows there's no work today.

The other day I came home a little late from work (37 minutes late, to be precise) and instead of laying patiently in the entrance to the living room like he always does, Jake pounced on me as soon as I got in the door, as if to say "Where have you been?" 

A few days later, because of the timing of a morning meeting close to my house, I didn't leave for work until later - and instead of being overjoyed with the prospect of extra time with his human, he curled up on the couch and looked at me like "You're still here?  It's definitely nap time."

Maybe it's the border collie in him, maybe he's got a touch of OCD, but either way, I've learned that a regularly scheduled human makes for a happy dog.

How about you and your dog?  Do you have a set routine that you follow?