How to override variable in model?

Hi,

I am passing variable(run_date) to model at a run time, I have to change that value for one of the scenario(run_date -1 day) and use that. is there any way we can do that?

Thanks.

{% set run_date = var(‘run_date’) %}

{% if condition %}

{% set run_date = run_date -1 %}

{% endif %}