Of course, things like that happen. I'm not saying don't have a tuner. I am saying if your bass is losing tune that fast, and not because somebody bumped it, check it out, it shouldn't do that. And although we all use tuners of some sort, myself included, regardless of what instrument you play, you should be able to tune it to a piano or keyboard note, or pitch pipe, using your ears and only your ears. It's one of the very first things you learn. If you can't, lose the tuner and tune your ears.......then go get a tuner again.