Left my computer open overnight. At 8 pm last night both email providers were 6 hours ahead. At 4 am, Earthlink was the right time and ProtonMail was ahead. Restarted computer at 7 am. Both emails were the right time. Checked again at 9:30 am and both had jumped ahead.
Edit: as of 12/25 I have had 4 days of the right times on my emails. Thanks.