The people in his mosque pray Fajr before the proper time; should he pray with them?

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Check below answers in case you are looking for other related questions:
Using a timetable to know the times of prayer
The true time of Fajr

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Related Answers:
He cannot perform the prayer on time because of his work. What should he do?
The extent to which delaying prayer may be forgiven in the case of women
Delaying Fajr prayer until the sun has almost risen
Using a timetable to know the times of prayer
The true time of Fajr

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