All time information is stored as a 100 Nanosecond value to be as accurate as possible. For videos that are recorded at 25 fps (frames per second) this is fairly easy because one frame = 40 milliseconds. For videos recorded at 29.97 fps, the timing is never that clean (1 frame = 33,3667 milliseconds)
When logging time information INTERACT stores a time value corresponding to an multiplication of a frame duration. Due to latencies caused by the video (codec), using videos with different fps, or other reasons, your file may contain time information that is not perfectly matching the current frames per seconds value of the file.
When displaying your time information in the default Timecode format - showing frames for the last two digits, you cannot see this.
Duration calculation in the statistics is always based on the whole frames you see, so usually, it is not a big deal.
If you make use of routines like the State-Space-Grid or the Pattern Segmentation, the issue might becomes apparent, though.
These routines work with the millisecond information instead of the frames, which means that even if your time information looks perfect to you on Frame-level, there might be tiny gaps and overlaps on the millisecond level.
For gaps, the State-Space-Grid will show a lot of tiny circles in the bottom left corner (or the first column or the bottom row). Dialing the option Show empty codings removes these 'errors'.
When using the Create coding patterns command, tiny overlaps will result in many very small Events (often just a single frame) that will falsify the frequencies.
To eliminate those hidden 'errors' one mouse click is sufficient:
▪Click Transform - Time Values - Align 
to take care of any discrepancies.
All start time and offset times are correctly rounded to a multiplication of a frame duration based on the current FPS value of your data file.
| TIP: | If you temporarily switch to a time format that shows a millisecond value, you can see that the last 3 digits now show a repeating regular value. For example, at 25 fps, you see only these values as the last 3 digits: .040, .080, .120, .160, .200, .240, etc. |