Ideal if you've been held up and you can't get back in time for your dog. There is no need to be stressed out, give me a call and I will get to your dog as quickly as possible to let him/her out and just check that they are ok. Or it could be a regular arrangement say for a older dog or puppy that needs to be let out regularly or just needs checking on whilst you are out. I always carry chews, so that will keep them happy until you get home. A text will reassure you all is ok, so you can drive safely home out of the rush hour traffic.