I doubt that you will have to. With today's electronics, I think many of them have a built in timing reference, like a 32 khz crystal. It's the old motor driven clocks that use synchronous motors that will have an accuracy problem.
Properly generated line power keeps better long-term accuracy than a 32.768 crystal oscillator, which is the timebase of any 'quartz' wristwatch. Most of these are good for about a second a day systematic error, which the makers appear to run about that fast; this makes it easier to resynchronize the watch to a trusted time source, simply by pulling out the stem for a few seconds once in a while.
Complications arise with a line-frequcny clock when you have blackouts, of course; they're an inconvenience on the same order as your watch battery running out.
Nowadays, many clocks and some watches have Very Low Frequency receivers for NIST station WWVB, or equivalents in Europe and Asia. These timepieces are the ones touted as 'atomic.'
A few, but not many, clocks and appliances have an internal 32.768 KHz oscillator to back up their line frequency time base. A good combination, but not that common. The 'atomic' timebase is, I think, the more common type by now.
By the way---My most recent watch, a Seiko chronograph, comes amazingly close to zero. I believe it stays within about two seconds per month. Even after falling on it, smashing the crystal, and having it fixed.
Apropos of very little, here's a bit of trivia.
One of the inventors and early marketers of the electric clock was a man by the name of Laurens Hammond. He went on to become better known as the inventor of the electronic organ.