I've never had a problem with any of my basses needing tuning except in extremes of temperature & humidity. As long as the strings are bedded in properly when you change them they can go for weeks with out tuning.
...and by bedding in I mean grab hold of the string and give it a darn good wiggle with around 1" deflection, which evens out the tension in the machine head wrappings, string trees, nut, etc. Don't be afraid of breaking the string, as if it's gonna let go then now is the time to do it rather than at a gig.