Getting rows of a day by timestamp, Day/Minute of certain pattern

id   name     quantity    timestamp
1    item1     2         2015-06-01 20:00:00
2    item2     5         2015-06-01 22:30:00
3    item3     2         2015-06-02 20:00:00
4    item4     7         2015-06-02 20:30:00
5    item5     9         2015-06-02 21:30:00

This is an example database, 'timestamp' is in datetime format and contains varying values. Note that the table contains various date and time data. How do i get all the rows of one day and of certain minute(above eg: 30) only, eg how can i select all the rows with timestamp 2015-06-01 **:30:00, here ** = hour any help, thanks.

via Chebli Mohamed