Chronometer Subtitle Creator is a web utility developed to easily display a digital chronometer or clock on a video. It can be used for amatorial or scientific purposes thanks to arbitrary settable precision. That utility creates a .SUB file ready to be used.
Obviously Chronometer Subtitle Creator is not enough but you can find a short guide to succes below (apply it to Windows users) and two video examples. In the end of page you can find some useful links in video subtitling subject. Finally feel free to contact me at my e-mail address for bugs report, suggestions, request of features, compliments and expression of regard. Insults are welcome too.

Settings:

Chronometer file creation impossible. Check fields marked in red.
Chronometer file creation impossible. File exceeds maximum length permitted (5 Mbytes).
Set initial date and time (set initial time to midnight if you want a chronometer instead a clock)(1) hours minutes seconds
day month year
Time and Date format (syntax) (*)
Example: 23/07/2008 - 22:07:14
 date separator time
Set how many decimals have to be displayed (for seconds)    
Text before and after time and date indication (it is advisable do not insert too much characters) before after
 
Set video file duration (2) hours minutes seconds
 
Set the video fps (frame per second, a.k.a framerate) value (3)
If the movie isn't at real speed, set playback speed in percentage (100% is realtime) %

(1) Do not insert dates prior to midnight, January 1, 1970
(2) Total amount of duration time must be greater than 0 seconds
(3) Is required to insert a fps value
(*) If date format is omitted, initial date will be automatically set to today
Note 1: Using double quotes (") will cause the wrong return of the strings
Note 2: The maximum file length permitted (evaluated) is 5 Mbytes

Short guide to success

  1. Use Chronometer Subtitle Creator web utility to create a personalized chronometer .SUB file
  2. Download SUB to SSA, an utility that converts SubRip/MicroDVD substitles to Sub Station Alpha scripts.
    1. Usage and features are optimized to make standardized subtitles and SSA scripts to use them in VirtualDub subtitler plugin
    2. Select input and output files. After selecting input file you have to specify framerate (fps) of the video you want to subtitle (you can get fps value directly from video file)
    3. You can change font, color, and others override options before clicking on Convert to .SSA
  3. Download VirtualDub, a powerful stand-alone utility for video capture and video processing for 32-bit Windows platforms (95/98/ME/NT4/2000/XP).
  4. Download subtitler (that is in the VirtualDub's website too), a VirtualDub filter that applies Sub Station Alpha v2.x/4.x scripts to video.
    1. Copy subtitler.vdf into the PLUGINS\ directory in the VirtualDub program directory. Then the filter will automatically load when the main program starts
    2. Make sure that Full processing mode in Video menu is selected
    3. Select a video codec, like DivX, from Compression in Video menu, to save disk space.
    4. Now you are ready to render the chronometer on your video:
      1. Click on Open video file on File menu
      2. Add the subtitler filter selecting Filters on Video menu and select the .SSA file previously created in the Configuration window of subtitler.
      3. Click on Save as AVI on File menu and choose the filename.

Video Examples

Two video examples are available here.

Acknowledgments

Thanks to Letizia Gagliardi for helping me with english grammar mistakes.