For scripts that run before or after the graph is drawn, see Graph draw events.

Visible Range Min. Argument_CurrentMinimumValue and Argument_CurrentMaximumValue contain the current automatic Bottom-axis range. A numeric Result sets the minimum and disables the automatic minimum. A NULL result sets the minimum to 0; with no formula, the automatic minimum remains enabled.
Visible Range Max. It receives the same original Bottom-axis arguments as Visible Range Min; the arguments are not refreshed after the minimum formula. A numeric Result sets the maximum and disables the automatic maximum. A NULL result sets the maximum to 0; with no formula, the automatic maximum remains enabled.