Come to find out that this was some sort of entrenched, company-wide standard that was deliberately imposed. I made a lot of noise about this and appealed to some rather highly-placed directors, because I felt like it was wildly inaccurate and deceiving people; if you schedule a meeting in EDT but you say it's in EST, and we have employees all around the world, who's going to know? You're inviting off-by-one errors. Especially with me who lives permanently in MST.
3 years on, I've been unable to change this fundamentally; while a few people acknowledge DST, 90% of the company still adheres to this crazy false standard.