Thomas G. Shanks is an American computer programmer, author, and time zone

Time zone

A time zone is a region on Earth that has a uniform standard time for legal, commercial, and social purposes. In order for the same clock time to always correspond to the same portion of the day as the Earth rotates , different places on the Earth need to have different clock times...

 history researcher.

Work

While working for a San Diego based astrological computing company as programmer and research director, Shanks did extensive research in the field of worldwide timezone and daylight saving time

Daylight saving time

Daylight saving time —also summer time in several countries including in British English and European official terminology —is the practice of temporarily advancing clocks during the summertime so that afternoons have more daylight and mornings have less...

 history. He published the results of this research in the two volumes The American Atlas and The International Atlas. Shanks' published data are quoted frequently in the public domain

Public domain

Works are in the public domain if the intellectual property rights have expired, if the intellectual property rights are forfeited, or if they are not covered by intellectual property rights at all...

 tz database.