This is a very difficult question to answer as everyone is different. And the phrase 'out of action' doesn't really make any sense. Minimally invasive surgery however is usually associated with very little "down time". Most patients are encouraged to walk the next day. Single level disc replacements at L5/S1 usually require an overnight admission, 6 weeks without driving and provided you can work without the need to drive a car, return to work 2-3 weeks later performing light duties. These patients return to exercise 6 weeks later and simply need to be careful and exercise common sense for 4-5 months while the prosthesis bonds.
On the other hand, complex revision surgery with chronic nerve damage requiring multiple approaches may take a year or more to recover from with time before that using walking aids.
No two patients or surgeries are the same. If you can gauge where you lie within these two extremes you will get an idea of your downtime. Generally, I advise patients to plan for the worst and hope for the best. Most patients tend to get their life back and be on the road to recovery 4-5 weeks post-op.