My mechanical automatic watch

For my fiftieth birthday Jan bought me a great watch I had lusted after for years, it cost an arm and a leg. It was second hand but in as new condition. It's a mechanical automatic, 15 years on it needs a service and does not run for the stated 30 plus hours, although still keeps perfect time. Here's the rub, If I have a very busy day with lot's of activity it runs through the night, when I have a lazy day it packs up around four or five in the morning. Because of this I call it my lazyometer. Last night it stopped before I went to bed. Time to get this sofa unbolted from my arse methinks, I blame the weather.