The CenturyTimer calculates and displays countdown or count up time, every 30 seconds. It can be set in one-minute intervals, ranging from January 1, 1900, at 12:00 AM to December 31, 9999, at 11:59 PM. It calculates and continuously displays the time, which changes every 30 seconds. Time is displayed in days, hours, minutes, seconds, deciseconds, Centiseconds, Milliseconds, Microseconds, Shakes (100 millionth of a second), and Nanoseconds (1 billionth of a second).

The CenturyTimer is easy to use. Just change the date and time in the five input boxes to the date and time that you prefer. The date you set can be in the future, or in the past. That is the CenturyTimer counts down to a designated end date, or counts-up FROM a designated start date. When the date is in the future, a negative sign (-) is displayed in front of the readouts, and the absolute value of the numbers displayed decreases with time, until it reaches zero. After this point, it starts counting upward with positive numbers. If you want to see how this works, you can easily set the CenturyTimer to reach a time zero that is a few minutes in the future.
If the CenturyTimer is set to count up, from a designated start date the readouts are displayed with positive numbers, (without a negative sign.) For a good example of the above, set the CenturyTimer to the date and time that you were born. The readouts will indicate how many days, hours, minutes, and seconds that you were alive. These numbers will increase every 30 seconds, because you are constantly getting older.

Instructions and other information are embedded in pop-up notes. To read these notes place your mouse cruiser on the word PopUp.

Delete the number in the white box below, and enter the day of your start date or end date. Use numbers from 1 to 31. Remember to left click on the box, before deleting or entering numbers.

Delete the number in the white box below, and enter the year of your start date or end date. Use four digit numbers for the year. Remember to left click on the box, before deleting or entering numbers.

To enter the hour of your start date or end date, left click on the white box below. When this is done a menu will open, with hours ranging from 12:00 AM to 11:00 PM. Scroll up and down the menu to find the hour you want, and left click on it. Keep in mind you must enter the hour and minutes separately. For example, if you want 12:37 AM, you will enter 12:00 AM in this box, and 37 minutes in the next box.

To enter the time in minutes of your start date or end date, left click on the white box below. When this is done, a menu will open, with numbers ranging from 0 to 59. Scroll up and down the menu to find the number you want, and left click on it. Keep in mind you must enter the hour and minutes separately. For example, if you want 12:37 AM, you will enter 12:00 AM in the hour box, and in this box, you will enter 37.

Decisecond is a 10th of a second (1 second = 10 ds)

Centisecond is a 100th of a second (1 second = 100 cs)

Millisecond is a 1000th of a second (1 second = 1000 ms )

Microsecond is a millionth of a second (1s=10^6 microseconds)

A Shake is a 100 millionth of a second (1 second = 10^8 shakes)

A Nanosecond is a billionth of a second (1 second = 10^9 ns)

This Timer has an automatic mechanism to make corrections for daylight savings time, when it is COUNTING DOWN to an end date. This mechanism can be turned off by placing the letter X in the white input box. This is useful if you do not have daylight savings time in your locality.

The user can make corrections manually for Daylight Savings Time, by entering positive or negative numbers in the adjacent input box. This generally involves a correction of plus or minus one hour, which means entering 1 or -1. When a number is entered, the correction mechanism for Daylight Savings Time is automatically turned off.

In this box, TIME ZERO is displayed, which might be different from the user setting, because of automatic or manual corrections for daylight savings time.

If the START date for Daylight Savings Time is NOT correct for your locality, you can change the date and/or time by entering positive or negative numbers in the input boxes. To advance the date and/or time to a later period, enter positive numbers, such as such as 1, 2, 12. For an earlier period enter negative numbers, such as -1, -2,-12.

If the END date for Daylight Savings Time is NOT correct for your locality, you can change the date and/or time by entering positive or negative numbers in the input boxes. To advance the date and/or time to a later period, enter positive numbers, such as 1, 3, 18. For an earlier period enter negative numbers, such as -1, -3,-18.