The time bar below the edit window is a visual aid for estimating the readability of the current subtitle. When the bar is very short (0-66%) and still in the left red zone the subtitle may only be read by very fast readers.
When the bar is in the yellow zone (67%-99%) most viewers will probably be able to read the subtitle, though it is still not optimal.
And when the bar is far into the right red zone (over 150%) the subtitle exposure is probably too long.
The optimal duration is achieved when the bar is centered around 100%.
What's optimal, however, is relative. Titlevision's criteria for an optimal duration are based on a standard of 10 characters per second. But in the rather complicated computation for this routine we have also tried to allow for the fact that it takes more time to locate and read a short subtitle than a long one. And that it does not require the same amount of time per character to read two lines than to read only one.
The user should also consider that although most viewers will be able to read one single subtitle in the yellow zone, this will not apply to a longer series of subtitles. So:
Always try to obtain the optimal duration
This being said, also consider that subtitles with difficult words or a complex phraseology may need a longer exposure.
If you find our standards for reading speed either too slow or too fast you can change them in "miscellaneous settings" under Setup/Preferences.
The time bar may be disabled in the Layout Configuration Menu.
See also:
Miscellaneous settings