There are cases where in order to avoid extrapolation we fill the beginning and/or end of a file with nan values. In reality we want to be interpolating between the times (as an example) 13:59:58 from the previous file and 14:00:01 from the beginning of the next file instead of setting values between them as nan.
There are cases where in order to avoid extrapolation we fill the beginning and/or end of a file with nan values. In reality we want to be interpolating between the times (as an example) 13:59:58 from the previous file and 14:00:01 from the beginning of the next file instead of setting values between them as nan.