org-agenda-remove-times-when-in-prefix

org-agenda-remove-times-when-in-prefix is a variable defined in `org-agenda.el'.
Its value is

t

Documentation:
Non-nil means remove duplicate time specifications in agenda items.
When the format `org-agenda-prefix-format' contains a `%t' specifier, a
time-of-day specification in a headline or diary entry is extracted and
placed into the prefix. If this option is non-nil, the original specification
(a timestamp or -range, or just a plain time(range) specification like
11:30-4pm) will be removed for agenda display. This makes the agenda less
cluttered.
The option can be t or nil. It may also be the symbol `beg', indicating
that the time should only be removed when it is located at the beginning of
the headline/diary entry.

You can customize this variable.