Posted this in the legal advice subreddit but thought maybe it would be okay to ask for advice here. If I am wrong I apologize.
About 9 days ago I called my work to give them a heads up that I would be late. I clocked in 9 minutes after my scheduled time and I got an email a couple hours ago before midnight from my manager stating that it is a final warning and failure to comply would result in termination. The thing is that they sent it to me 15 minutes before midnight. Sending it in after midnight would be 10 days and at my job there is a protocol where management needs to file complaints within 10 days of the incident otherwise it would be obsolete. My manager gets off work after 3PM, meaning that he sent this during his non-work hours.
Is this legal? Am I obligated to sign this? We also have a union so maybe it's better to ask them but I thought I would try asking around here.
Thank you for any advice.