Dodanie znaków do selecta

'CONCAT(LPAD(pwh.open_from_hour, 2, 0),\':\',LPAD(pwh.open_from_minute, 2, 0)) as open_hour_from',
'CONCAT(LPAD(pwh.open_to_hour, 2, 0),\':\',LPAD(pwh.open_to_minute, 2, 0)) as open_hour_to',

Jeżel:

open_from_hour -> 0

open_from_minute ->

to powstanie

open_from_hour -> 00:00