Countdown Timer with Markers
 by nikhil bhatla,,
 more web apps at
 published Nov 16, 2010 (version 1)

This web-app is a simple stopwatch that I use for some of my science experiments. Specifically, you can use it to record when an observed event occured. Let's say you're interested in traffic patterns, so you want to count the cars driving by on the street over the next hour. Each time a car drives by, press the spacebar. The program will record not only that a countable event occurred, but also when that event occurred. After counting cars for, say, 5 minutes, you not only have how many cars went by but when each car went by.

I made this app so I could more easily score when the nematode C. elegans' pharynx pumps (i.e. chews). I set the timer to 10 sec, and then count the number and timing of pumps during that time under different conditions and with different mutants. I normally see about 30 pumps in 10 seconds.

If you want to leave a comment or ask a question, check out the blog post.


  1. Enter countdown duration.
  2. Press SPACEBAR or the button to start.
  3. Press SPACEBAR each time an event of interest occurs, to record its timestamp.
  4. When time is up, you'll hear a chime. Any space bar presses after that will not be recorded (useful if you're observing a high frequency event like worm pumping).
  5. Copy and paste the times below into your favorite analysis program.
  6. Before starting again, press the R key (for "reset") to reset the timer. The countdown duration will stay the same. Then press SPACEBAR to start the timer again!

NOTE: Recording timestamps does NOT work in Internet Explorer.

NOTE 2 (Sep 2, 2015): Actually, testing this app in browsers on Windows 7 today, I find that the app only works properly in Internet Explorer 11, and not the current versions of Firefox or Chrome! How odd.

Countdown duration:  hr, min, sec

Total number of events:
Time (milliseconds from start)