During the winter season, I find myself baking more tasty food items for our family to enjoy. Whether it is a scrumptious dessert or a new dinner recipe, our oven gets more use when it's cold outside. In my days before kids, I used to be able to stick something in the oven, make note of the time I placed it in, and be attentive to when the cooking was complete and ready to be pulled out of the oven. With the addition of 2 children, my mind and life is much busier, and I rely on my kitchen timer to inform me when the cooking is done.
A kitchen timer is not only great for signaling the completion of food in the oven, but parents can use this as a great "signal" to their young children. Instead of telling your kids that it will be time to leave in 5 minutes (since children don't have a great concept or understanding of time, especially because it is abstract), use the timer to be the signifier.
If you find it hard to leave play dates, a fun day at the park, or a special day at a museum, bringing a portable kitchen timer (small enough to fit in your purse) works the same way. If you set the timer for 2 minutes at the park, it might also be helpful to tell your children they have enough time to go down the slide 2 more times (something concrete and tangible for them). When the timer goes off, it will be time to leave.
Using a timer reminds me of hearing the bell go off at recess when I was a young child in school. No one ever wanted to go inside, but once the bell rang, we all had to line up. How could you argue with a bell? Hopefully, the same can apply here with the use of the timer. Give it a try and see if it helps lower the meltdowns for your kids, while at the same time improving compliance!