# ⓘ Local mean time is a form of solar time that corrects the variations of local apparent time, forming a uniform time scale at a specific longitude. This measurem ..

## ⓘ Local mean time

Local mean time is a form of solar time that corrects the variations of local apparent time, forming a uniform time scale at a specific longitude. This measurement of time was used for everyday use during the 19th century before time zones were introduced beginning in the late 19th century; it still has some uses in astronomy and navigation.

## 1. Past use

Local mean time was used from the early 19th century, when local solar time or sundial time was last used until standard time was adopted on various dates in the several countries. Each town or city kept its own meridian. This led to a situation where locations one degree of longitude apart had times four minutes apart. This became a problem in the mid 19th century when railways needed clocks that were synchronized between stations, at the same time as people needed to match their clock or the church clock to the time tables. Standard time means that the same time is used throughout some region - usually, it was either offset from Greenwich Mean Time or was the local mean time of the capital of the region. The difference between local mean time and local apparent time is the equation of time.

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• Local time may refer to: Local mean time Local time mathematics Local time in the Lorentz ether theory
• UTC. The local mean time in Bangkok was originally UTC 06: 42: 04. Thailand used this local mean time until 1920, when it changed to Indochina Time UTC 07: 00
• observer s latitude and the season A mean solar day what we normally measure as a day is the average time between local solar noons average since this
• Coordinated Universal Time Local mean time a form of solar time that corrects the variations of local apparent time Washington Mean Time the time at the meridian
• from local mean solar time LMST for the lander site while the seventh Mars Pathfinder used local true solar time LTST The local lander time for
• Irish Standard Time IST, UTC 01: 00 Irish: Am Caighdeanach Eireannach in the summer months and Greenwich Mean Time UTC 00: 00 Mean - Am Greenwich in
• began to use local mean solar time Apparent and mean solar time can differ by up to around 15 minutes as described by the equation of time because of