I began workign for a Massachusetts auto dealership as a coop mechanic student. After 18 months I switched to fulltime work, and have been there for more than a year as a fulltime employee. I recently realized the compnay was only accruing vacation time from my date of fulltime hire, excluding the coop time. However, one of my coworkers, who went through the same school and coop program as me but was hired about 2 years earlier, has their time accrued from when their coop started, rather than finished.
Can I ask for a change of status and receive back vacation time. or at least be given the vacation time I'm owed. And if so, what is the best way to go about asking?
Thanks for the reply.

Vacation/Sick Time Accrued
I work for a daycare recently they had all employees that were full time downgraded to part time without notice. Now they are saying they are taking away our vacation and sick time and also no more holiday pay. Is this legal to do without notice? If it is not what are my options.