US Time Zone Converter

How does the US time zone converter function?

This tool is designed to be simple and easy to use and to offer you the exact information you need real quick. The first two fields are the current date and time and you can change according to your needs. Below there are two lines in which you need to choose the starting point for the international time conversion and the location for which you want to find the corresponding time. In the “From” an “To” sections you can choose whether you prefer a state or a capital and then narrow your search to the specific location in the second dropdown. With the US time zone converter you can make conversions and display the international time from a state to another, a capital to another capital and even between a state and a capital. The calculations are based on this simple conversion:

"time in zone A" − "UTC offset for zone A" = "time in zone B" − "UTC offset for zone B",

in which each side of the equation is equivalent to UTC. The conversion equation will then be arranged  to: "time in zone B" = "time in zone A" − "UTC offset for zone A" + "UTC offset for zone B" in order to provide the desired result from the data the users input.

Coordinated Universal Time (UTC):

This represents the modern civil time and has been defined since January 1972 to follow the International Atomic Time (TAI) with an exact offset of an integer number of seconds. Greenwich Mean Time (GMT) is an older standard, adopted starting with British railroads in 1847. GMT was calibrated to the mean solar time at the meridian passing through the Royal Observatory in Greenwich, UK. This time keeping method is less exact than the UTC because the rotational period of Earth is not perfectly constant and the duration of a second would vary if calibrated to a telescope-based standard like GMT.  

Since 1972 all official time services have broadcast radio time signals synchronized to UTC, a form of atomic time that includes leap seconds to keep it within 0.9 seconds of this former GMT. Within this implementation most nations began to use the UTC standard when defining their time zones instead of the former GMT definition. A UTC time offset is the amount of time subtracted from or added to UTC to get the current local time for a specific location. Offsets from UTC are written in the ±[hh]:[mm] format.

Time Zones define the geographical regions that observe a certain standard time. Most time zones are one hour apart and their boundaries are settled by the longitudinal lines of 15°. By convention, every time zone computes local time as an offset from UTC. The reference point for UTC is the Greenwich Meridian (the Prime Meridian), which has a longitude of 0°. Local time adds 1 hour for every 15° going east and subtracts an hour for each 15° going west. Many locations change the offsets during summer months to define the usage of Daylight Savings Time (DST).

Daylight Saving Time (DST):       

DST, also known as summer time represents the practice of advancing clocks  in the summer months so that afternoons have more daylight and so electricity costs would be reduced. The one hour shift occurs at 02:00 local time shifts to 03:00 local time in spring and from 03:00 to 02:00 in autumn. To know how the clocks go just remember “spring forward, fall back”. Each country has established dates in which to make the switches for the following years. Northern and southern hemisphere countries are the ones that use in a larger number DST while near equator DST is not that used because sunlight changes are minimal there.

United States Time Zones:

Daylight Saving Time begins at 2:00 a.m. local time on the second Sunday in March. The US returns to the Standard time on the first Sunday in November Standard Time at 2:00 a.m.  The table below shows the nine standard time zones in the United States, their corresponding DST time zones and the states that follow that.