st: combining consecutive similar observations in time series datasets

[Adeel Yousaf <townplanneradeel@gmail.com>]

Hi,
how can I combine multiple rows of an activity to one row and generate
its start and end time, in panel dataset, if the activity occurs
adjacently. For example, in the first table 1 the activity code "11"
has 3 rows from 4:00 am to 5:30am, I need to get its compact form
shown in second table  :-

actual dataset:-
id      start   end     coded
100003  4:00    4:30    11
100003  4:30    5:00    11
100003  5:00    5:30    11
100003  5:30    5:45    13
100003  5:45    6:00    14
100003  6:00    6:30    14
100003  6:30    7:00    14
100003  7:00    7:15    15
100003  7:15    7:30    16
100003  7:30    8:00    16
100003  8:00    8:15    16
100003  8:15    8:30    17
100003  8:30    8:45    15
100003  8:45    9:00    15
100003  9:00    9:30    15
100003  9:30    10:00   15

what i need is:-
id      start   end     coded
100003  4:00    5:30    11
100003  5:30    5:45    13
100003  5:45    7:00    14
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