var fixTraceIds = function(name){
	db.getCollection(name).updateMany(
		{$expr: { $gt: [ { $strLenCP: "$traceId" }, 16 ]}},
		[{$set: {"traceId": {$substr: ["$traceId", {$subtract:[{ $strLenCP: "$traceId" }, 16]}, 16]}}}]
	)	
}

var doForDateRange = function(dateStart, dateEnd, func){
	var
    aDay = 24 * 60 * 60000,
    from = new Date(dateStart),
    till = new Date(dateEnd),
    date = from;
    
    while(date <= till) {
        dateStr = date.toISOString().split('T')[0];
		func.call(this,dateStr);
        date = new Date(new Date(date).getTime() + aDay);
    }
};

doForDateRange('2021-07-09','2022-02-15', fixTraceIds);