Dallas is 2 hours behind Montevideo
Best overlap: 10:00 AM to 6:00 PM in Montevideo is 8:00 AM to 4:00 PM in Dallas.
Plan around 10:00 AM to 6:00 PM in Montevideo, which is 8:00 AM to 4:00 PM in Dallas, to catch everyone during office hours. Dallas is 2 hours behind Montevideo, but you'd hardly notice — 8 hours of shared hours makes this feel like working in neighbouring time zones. Note that Dallas follows daylight saving while Montevideo stays put, so the times above drift by an hour seasonally.