There was a team of analysts going through all the companies programs and finding any instance of dates, which took them quite a while to do. Once that was done it was a combo of new work and work to update the affected programs. My team was very affected as it was the collections and queuing team. Collections of course is people going into collections due to non payment. Queueing is the different queues you put accounts into: 30 days past due, 60 past due, etc. all of that broke when the date changed as all accounts were way past due and put into collections.