[jsmith45]

Yeah. there is a minimum dwell time, and the door close button will never close the door sooner than that on modern code compliant elevators in normal operating mode.

It is possible that there will be a default dwell time that is larger than the minimum, in which case the pressing the door close button would shorten the window to the minimum, but most elevators won't do that as the minimum is long enough already.

Similarly the door close button may have effect when the door open period was extended, such as by the door sensors, or pushing the door open button to prevent door closing, but the exact details will vary.

In other operating modes, especially firefighter mode, but also some maintenance modes, and some modes that expect a dedicated elevator operator (who can ensure the door remains open long enough for disabled people if present), the door close buttons do absolutely do have an impact, and can violate the normal dwell time rules.