Not sure how else I can clear this up. I'm GMT.
This is due 5AM GMT 18/12/17.
This is due 0AM EST-5 18/12/17.
We can agree on that yes? EST-5 = GMT. So then surely, EST = GMT+5.
It was bad enough having to write 0AM because most people write it as 12AM which is somehow correct but incredibly misleading. If they really messed up time to the point that + and — are reversed here, then I just don't even care anymore. I'll keep using it wrong until the world adapts. It's the 20th century, so we've had ages to get this right. Replace 12 with 0 on all clocks! It's time to fix time!