how to use rounddown function in excel

8:16

5:39

9:03

1:51

4:46

6:39

6:56

3:30

2:03

11:03

6:41

13:45

3:52

6:49

2:17

3:13

1:22

4:08

6:42

4:42

1:06:03

7:47

9:04

16:07

11:06

18:40

4:48

56:29

7:50

8:03

3:21

3:40

4:00

10:04

4:27

6:29

3:40

3:05

1:06:43

8:35