It is very clear in the ADA, you have to be accommodated.
You are not alone
"Take Stephen Orr, a former pharmacist with Wal-Mart. His first manager hired him under the agreement that Stephen, a diabetic, would close the pharmacy a half hour each day so he could eat lunch to keep his blood sugars steady over his ten-hour shift. A new Wal-Mart district manager came on the scene and didn't want him to take the lunch breaks, so they fired him.. "
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