Combining two date conditions with measurement

What is the right filter syntax to identify when a new client we are measuring is showing activity and the date of this first activity appeared.

For example my objective is to identify when client X went live per the measurement minimum activity.

Thank you in advance,

Since we can’t use MIN/MAX with dates in Looker the best way to do it is to add this column in your data model and just expose it as a dimension.

You can use this:

measure: first_date {
    type: date
    sql: MIN(${TABLE}.activtiy_date ;;
}

but you won’t be able to use it as a filter because measure can’t be filtered by another measure