I think you cannot. Even arbitrary sweep of temperature under transient analysis is not so possible.
But, are you sure the MOS parameter should be equivalent with time? Not so realistic, practical.
Maybe you want to sweep VT0 of the MOS in transient analysis, in that case connect a PWL voltage source in series with MOS gate terminal, and sweep the voltage.
I think you cannot. Even arbitrary sweep of temperature under transient analysis is not so possible.
But, are you sure the MOS parameter should be equivalent with time? Not so realistic, practical.
Maybe you want to sweep VT0 of the MOS in transient analysis, in that case connect a PWL voltage source in series with MOS gate terminal, and sweep the voltage.
I would look at simply adding a gate series voltage
source, which will have the same effect as a VT shift.
If you used a controlled or behavioral source then
you could make it time-variant or event-variant.