Responsibility or fun? Business or pleasure? We can actually have some of both, if we choose.
The 4 that keeps our nose to the grindstone and overseeing the responsibilities in life can give way to the 3 who would just as soon throw the lists up in the air...laughing. It's a good time to enjoy your customers a bit more while networking with others. If you are in retail, cultivate new clients with conversation and not "buy it, buy it, buy it" ads.
Ask your co-workers if you can assist them (if you have time). Take treats and snacks to work and celebrate..."Wednesday". If you're the supervisor, build up morale, even if you don't feel it yourself. Start off the morning/afternoon by giving some well-deserved compliments to the staff. It only takes a few seconds, but the rewards can be far more extensive than that. A steady dose of the over-critical 4 does nothing for improvement.
If you're at home, it's a "whistle while you work type" vibration, but you'll have to choose to sing and whistle and not get bogged down with "what needs to be." Find the fun in those chores and/or repairs that need to be accomplished. Bake bread or make coffee while doing something you're not thrilled about. Smells can often times help distract our minds while finishing a project. AND enjoying them afterwards is just plain fun!
This evening, concentrate on providing an enjoyable night for yourself and/or others. If you're cooking for others this evening, make it fun. 3 loves fun and easy (i.e. Pizza night). Bring in comedy DVDs, board games, cards, anything that's playful. It's a good way to end a day.