pouchDB find eq date (without time)

I use pouchDB find to get specific documents selecting by date, like :

    getByDate(date:Date): Promise<Array<Intervention>>{
        return this._db.find(
            "selector": {
              "int_planning_date": {
                "$eq": date.toISOString().substr(0, 10)

So I need to compare only date,
1- How can I convert my selector field in other format (from iso 8601 to date without time)
2- Or convert JSON date (saved document in this format)

Thank you !

Finally, I used string format instead of Date