timezone

Time zone based on longitude

Syntax

[zd,zltr,zone] = timezone(lon)

[zd,zltr,zone] = timezone(lon,units)

Description

[zd,zltr,zone] = timezone(lon) returns the integer zone description zd, the alphabetical zone indicator zltr, and the complete zone description and alphabetical zone indicator zone that correspond to the input longitude lon.

[zd,zltr,zone] = timezone(lon,units) specifies the angle units units for the longitude.

Examples

Find Time Zones Based on Longitude

Display the zone description and alphabetical zone indicator for each time zone, excluding +12 Y.

lon = 0:15:360;
[zd,zltr,zone] = timezone(lon);
zone

zone = 25×5 char array
    '  0 Z'
    ' -1 A'
    ' -2 B'
    ' -3 C'
    ' -4 D'
    ' -5 E'
    ' -6 F'
    ' -7 G'
    ' -8 H'
    ' -9 I'
    '-10 K'
    '-11 L'
    '-12 M'
    '+11 X'
    '+10 W'
    ' +9 V'
    ' +8 U'
    ' +7 T'
    ' +6 S'
    ' +5 R'
    ' +4 Q'
    ' +3 P'
    ' +2 O'
    ' +1 N'
    '  0 Z'

Input Arguments

lon — Longitude

numeric scalar | numeric array

Longitude, specified as a numeric scalar or a numeric array.

units — Angle unit for longitude

"degrees" (default) | "radians"

Angle unit for the longitude, specified as one of these options:

• "degrees" — Degrees

• "radians" — Radians

Data Types: char | string

Output Arguments

zd — Zone description

integer | vector of integers

Zone description, returned as an integer or a vector of integers. The data type of zd matches the data type of lon.

zltr — Alphabetical zone indicator

character vector | character array

Alphabetical zone indicator, returned as a character vector or a character array.

Data Types: char

zone — Complete zone description and alphabetical zone indicator

character vector | character array

Complete zone description and alphabetical zone indicator, returned as a character vector or a character array.

Data Types: char

Limitations

National and local governments set their own time zone boundaries for political or geographic convenience. The timezone function does not account for deviations from the meridian-based system.

More About

Time Zones

The position of the sun relative to the prime meridian (the zero longitude line through Greenwich, England) determines the time. When the prime meridian lies directly below the sun, the time is noon Coordinate Universal Time (UTC).

For local times elsewhere, the Earth is divided into 15° longitude bands (or zones), each centered on a central meridian. When a central meridian lies directly below the sun, Local Mean Time (LMT) in that zone is noon.

The zone description is the result of subtracting LMT from UTC. For notational convenience, each zone also has an alphabetical zone indicator.

The zone centered on the International Date Line (180° E/W) is split into two zones: +12 Y and -12 M.

Version History

Introduced before R2006a