As far as I know there is no absolute time measurement (one that would measure time in a non-environment-dependent fashion) in any life form. Only such time measurements exist, which are dependent upon cyclic changes like the strength of the sunlight, heat, amount of water, etc. (In case this assumption of mine is false, than please answer it in mind of life forms which in deed have only relative)
Theoretically, if we could change everything a given life form is dependent upon, could we increase it's entire lifespan?
For example if we were to put a plant inside a manually controllable environment and slow down the day/night cycle to it's third, maybe even decrease air pressure and the strength of gravity(thus eliminating any problem that might arise from the actual transport of water and the solution of organic matters produced in photosynthesizing cells), change (even though I'm not sure if this could be physically possible at all, but my whole question is theoretical, thus it should not cause a problem) the adhesion/cohesion as well (so the speed of transports in the cells would change accordingly) and change other, (for me) unthinkable aspects that, for example, regulates the time between cell divisions, would it live for longer?
Even if we could not change every aspect that regulates a given life form's working, changing many could we (although this time not linearly) increase it's actual lifespan?