Hello!

I am working with a longitudinal panel dataset collected from an online auction. For each observation, there is a time stamp that includes a date together with hour and minute, but no second. This results in a problem as there could be multiple observations in a given minute for the same id. The solution I seek your help implementing implies adding a single consecutive second to each of the duplicate time stamps. For example:

16mar2021 14:40:00 --> 16mar2021 14:40:01
16mar2021 14:40:00 --> 16mar2021 14:40:02
16mar2021 14:40:00 --> 16mar2021 14:40:03

The example of the data for experimentation is provided below. Your feedback is greatly appreciated.

Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input float id double datetime
11291 1.9309035e+12
11291 1930903680000
11291 1930903920000
11291 1930904280000
11291 1.9309059e+12
11291 1.9309068e+12
11291 1930907580000
11291 1930907880000
11291 1930907940000
11291  1.930908e+12
11291 1930908060000
11291 1930908180000
11291 1930915320000
11291 1930921260000
11291 1930989960000
11291 1931013240000
11291 1.9311711e+12
11291 1931271240000
11291 1.9313307e+12
11291 1.9313805e+12
11291 1.9313856e+12
11291 1931424480000
11291 1.9314276e+12
11291 1931432940000
11291 1931512740000
11291 1931512860000
11291 1.9315182e+12
11291 1931521260000
11291 1931521680000
11291 1931521980000
11291 1.9315221e+12
11291 1931522220000
11291 1931522580000
11291 1931522760000
11291 1931522880000
11291 1.9315233e+12
11291 1931524440000
11291 1931524440000
11291 1931524620000
11291 1931524620000
11291 1931524680000
11291 1931524680000
11291 1931524680000
11291 1931524680000
11291 1931524740000
11291 1931524740000
11291 1.9315248e+12
11291 1.9315248e+12
11291 1.9315248e+12
11291 1.9315248e+12
11291 1.9315248e+12
11291 1931524860000
11291 1931524860000
11291 1931524860000
11291 1931524860000
11291 1931524920000
11291 1931524980000
11291 1931525040000
11291 1931527740000
11291 1931537220000
11291 1931975880000
end
format %tc datetime