To offset the beginning of a fluid simulation you only have to set the Start of the fluid's domain to anything above 0 seconds. However, by doing so, the results differ from starting at time 0.
For example we can compare this two simulations with one inflow at 200 resolution in a scene with 1 second of duration (from 0 to 23 at 24 fps):
- The first simulation's Start and End are set from 0 to 1
- The second simulation's Start and End are set from 1 to 2
In this case the last frame of the first simulation may be the same as the first frame of the second simulation.
As you can see below, the result differ.
As this post says, this is the proper workflow when offsetting the beginning of a fluid simulation. However, in the offsetted simulation it appears that the inflow velocity is higher and thus there is more fluid.
This difference is more noticeable when you increase the resolution. I usually make a bake with Start 0 and then decide how many seconds of offsetting I'll put. Then when I bake again -with, say, 3.6 seconds as Start time- the result is a lot different from expected working at 650 resolution.
Then, the final question is, what's the proper workflow for offsetting the start of a simulation but maintain the result you might have when not doing so?