[Qgis-user] time in Attribute

[RMG]

Hello,

I am trying to figure out the duration between one day's survey begin time (e.g., 7:13:45) and end time (e.g., 9:39:53) in an attribute table of a line shape file. It has just two attributes begin and end. But $lengh returns an error message and cannot figure out the duration. I suspect that the fields are not in proper format. So, I try to update the fields with

to_time("begin")

Then, it says Eval Error: Cannot convert '7:13:45' to Time. 

What is a remedy? The “begin” and “end” are in string. 

Best wishes,

Reiko Matsuda Goodwin
Comoé Monkey Project
Guenon Conservation Community


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