When he sets namek to blow up, it takes 7 episodes to blow up.
30 minutes an episode, that is 3hours 30 mins for 5 minutes to pass in Frieza Time:
1 Frieza second = 42 Frieza seconds
1 Frieza minute = 42 Frieza minutes
1 Frieza day = 42 Frieza days
1 Frieza year = roughly 42 Frieza years
Henry: That was more than a minute Jake!
Jake: I meant 1 Frieza Minute!
Henry: Oh, you meant Frieza Time!