Clocks Created with Spreadsheet Software      


Created by David Alderoty 2012


This website provides software-based clocks

in the spreadsheet and JavaScript format

for local and international time


To contact the author (David Alderoty) use this

e‑mail address:, or left click

on the link below for a website communication form.


Link for a Website Communication Form



This website also provides LINKS to a number of other websites created by the author that provide free downloads of various types of practical timing devices, and information on time management, which are presented below: (This lists a number of websites)



The Software on This Website, And The Downloads 


Below there are timing devices that were originally created with Microsoft Excel, but they were electronically converted to JavaScript so that they can function over the Internet, in conventional web browsers.  If you are interested in practical use of these devices, or you want to study the formulas and code used to create the devices, you can download zipped folders with the Excel and JavaScript versions, with the links presented at the end of this paragraph.  The Excel versions with the words Formula Study provide direct access to the formulas used to create this software.  The Excel versions are available for Excel 2003, and 2007-2010, in the same folder.  The Excel devices require Windows and Microsoft Excel, and the JavaScript devices should function with any modern operating system, but it was only tested with Windows. Remove the software from the zipped folder before you use it. This applies to both the Excel and JavaScript versions.

Left click on these words to download a zipped

folder with the Excel versions of the clocks



Left click on these words to download a zipped

 folder with the JavaScript versions of the clocks




Important Note about Timing Devices

Created With Spreadsheet Software


It is important to understand that timing devices that were created with Microsoft Excel, or similar spreadsheet software, must be updated to obtain the correct time and date.  For example, if a timing device created with spreadsheet software is opened on your computer on August 23, 2012, at 4:26 PM, it will indicate the above time and date.  This date and time will not change, even if you leave the software opened on your computer for a week, unless you update it.  You can update the spreadsheet versions either by entering or deleting numbers, and clicking with the mouse, or by opening and closing the software.  When a JavaScript timing device is created with spreadsheet software, the exact same concept applies.  That is the software will not register any changes in date or time unless it is updated as indicated above.   However, with the JavaScript versions, I often provide an update button, which the user can press to update the date and time.

      All of the above usually does not result in any practical problems, because most people frequently open and close software, and/or enter or delete data, which automatically updates the time and date.  When this is a problem, alternative timing software should be used.  


Another Important Note


The date and time displayed on the timing devices created with spreadsheet software, including JavaScript versions, access the date and time on your computer's clock.  Thus, if the time and date on your computer is incorrect, the date and time on the spreadsheet and JavaScript software will also be incorrect.  If the timing mechanism on your computer malfunctions, this will also be reflected in the time and date displayed by the software.

The JavaScript software on this website

Below there are five links to open five online JavaScript devices.  This is followed by a JavaScript device that is embedded in this webpage, which contains all five devices.  To open the link left click on it with the mouse, and for the embedded version scroll down.  


A Clock for Local Time



A Clock for Local Time and Date



ADJUSTABLE Date and Time Clock,

 for a time zone outside of your locality



A Clock for Multiple Localities

with Multiple Time Zones



All of the above in a single JavaScript device


Four Digital Clocks for Local And International Time
  A Clock for Local Time  
  A Clock for Local Time and Date  
ADJUSTABLE Date and Time Clock, for a time zone outside of your locality
  The clock presented below, is for keeping track of time in foreign countries, or in any locality that is in a different time zone from the area where you reside. The clock below is set for the time in London, based on the time in New York City, (Daylight savings Time). London time is five hours later than the time in New York, based on daylight savings time. If you are viewing this website in California, Beijing, Paris, Kampala, or anywhere else in the world, the time on the clock will be incorrect. If you are viewing the clock, when daylight savings time is not in effect, the time will also be incorrect. However, the time can be adjusted for any locality as explained below:  
  With this clock when a positive number is entered in its white input box, such as +5, the time is advanced five hours. If a negative number is entered in the input box, such as -3 the time displayed will be three hours earlier than the time on your computer clock. After adjusting the time, it is necessary to enter the locality in the yellow input box. With the example presented below, the input box has the words: The Time in London, (UK) is: These words can be deleted and you can enter any locality you choose.  
  A Clock for Multiple Localities with Multiple Time Zones  
  Below, there is a system of nine clocks, for multiple localities, with different time zones. one of the clocks is set to Greenwich Mean Time which controls all of the clocks in the system. This design concept, eliminate some of the disadvantages of the clock presented above, and it also keeps track of eight time zones simultaneously.  
  The advantage with this design concept is if you move from one time zone to another, you only have to check and readjust the Greenwich Mean Time. The readjustment is necessary for the Greenwich Mean Time because, it is interpreted in terms of the local time on the computer's clock. However, the eight clocks representing different time zones do not have to be readjusted if you move from one locality to another.  
  NOTE: If you are dealing with a locality that uses daylight savings time, (or the equivalent European Summer Time ) you have to readjust the Greenwich Mean Time. You may also have to adjust some of the other clocks on the system, to compensate for the above. You can check the time in any locality with an Internet search.  
  To use this clock, you must set the Greenwich Mean Time, by entering an appropriate number in the white input box in the red section, with the words Greenwich Mean Time (see below). For New York, during daylight savings time, the correct number is -4. This is usually presented as GMT-4:00. Once the Greenwich Mean Time is set, you can set the time zones for specific localities, in a way that is identical to the above. For example, (based on the summer months) California is GMT - 7:00, Texas is GMT-5, New Mexico is GMT-6, Tokyo Japan is GMT+ 9, Rome Italy is GMT+ 2, Sydney Australia is GMT+10 and Bangalore India is GMT+ 5:30. Note, when the number involves a fraction of an hour, enter it in decimals. With the above example, (Bangalore) to enter GMT+ 5:30, enter 5.5.  
  Below each white input box, there is a yellow input box to enter the locality that relates to the time setting, such as (USA) California Time.  
  NOTE: You can find the correct GMT number for any locality  
  at the following website  
  You can also find the correct GMT number for any locality by doing a Google search with the search phrase GMT locality. Specific examples of search phrases are GMT New York, GMT Tokyo Japan, GMT Rome Italy  
  To see if the Greenwich Mean Time is set correctly, left click on the link below  
    Greenwich Mean Time is    
  Keep in mind, all of the above settings are based on the time for the summer months, which may change in some regions during the winter months. However all of the numbers and words in the white and yellow input boxes can be deleted. Thus, you can make any adjustments that are required for the winter months, and you can also enter any time zones and related settings for any locality on Earth.