# Travel >> Travel Preparation >> Travel Itineraries

How to Convert CST to EST

The size of the continental United States, more than 2,000 miles from coast to coast, means the sun rises on the West Coast more than three hours after it appears on the East Coast. Until the 19th century, multiple local time zones existed across America. But as the railroad network grew, this became impractical, and in 1883 the railroad industry's General Time Convention established four standard time zones: Eastern, Central, Mountain and Pacific. The standard time difference from coast to coast is three hours, with Eastern Standard Time running one hour ahead of Central Standard Time.

Clock
Pen and paper

Instructions

Instructions
- 1
  Note the time on the clock if you want to convert the local time from CST to EST. Select the desired time of day if you want to convert a time of your choosing.
- 2
  Write down the time of day that you want to convert. Set out the time in HH:MM 24-hour format. For example, if the time is a quarter after 3 in the afternoon, write 15:15.
- 3
  Add one hour, the difference between CST and EST, to the value of the hour that you have written down. For example, if the time you have written is 15:15, the new time will be 16:15.
- 4
  Check whether the new value of the hour is 24, and if so, change the value of the hour to 00. Leave the value unchanged otherwise. For example, if your new time is 24:15, the converted time will be 00:15, and if your new time is 16:15, your converted time will remain 16:15. The result is the time converted to Eastern Standard Time.
- 5
  Record your result. Remember that if you have changed the value of the hour to 00, your converted time falls the day following your original time.