This game will take your date of birth, and expected life expectancy and calculate how many hours/minutes you have left to live. it is accurate down to the minute and will take the current time of day for the calculations. this means even if you close the page and reopen it, the time will be the same and continue to count down.
to change your life expectancy just click the box in the top left corner
note: tabbing out of the window, or opening a new application will stop the clock from running, but reloading the page will update it to the correct time