Exchange calendar events out by an hour

I wonder if anyone has come across a calendar syncing issue. I use a MacBook, and iPad and an iPhone 6+ for work, all synced to my exchange server. When I enter an exchange appointment on my MacBook and invite attendees all is good. But if I enter the event on my iPhone or iPad, the event comes up an hour early on the attendees calendar. If the same attendee creates an event (from a computer (non Mac) or their iPhone) and invites me all is good. I have tried all the time server settings that I found threads about when I googled the problem, but nothing has resolved it. Extremely frustrating!