Explore : How to create a date metric using the update date of a drop down field ?

Hi all !

I want to know if something is possible or not in Zendesk Explore.

I have a drop down ticket field.I want to create a date metric in Zendesk that will give the update date of the ticket field for a specific value.

For example :
for the ticket field "Order status", I want to know the date when the value "Validated" have been selected.
It's important for me to have a date metric because I will then calculate the average time between two actions after that.

For Example :
DATE_DIFF([Order Validated - Date],[Start date - Date],"nb_of_days")

Is it possible ? if yes, any tips on how to do that ?