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4. Standalone scripts

These scripts are used to perform some common operations from the Unix command line:

These scripts all require you to express times, angles, and similar units on the command line. Please refer to these sections for these common notational conventions:

4.1. Specifying dates and times on command lines

The scripts in this package require dates, with or without times, in this format, which is taken from the ISO standard date/time format:


The “T” separating the date and time is not case-sensitive.

Without the zone specifier, the time is assumed to be UTC (Greenwich time). You may also specify these zones (not case-sensitive):

±hhmm Hours and minutes east (+) or west (-) of UTC. Example: -0700 for Mountain Standard Time.
UTC Universal Coordinated Time, roughly Greenwich Mean.
EST Eastern Standard Time, -0500.
EDT Eastern Daylight Time, -0400.
ET Eastern Time: either EST or EDT depending on the date. At this time, the package supports the U.S. rules for daylight time, assuming that dates before 2007 change on the first Sunday in April and the last Sunday of October, and that 2007 and later change on the second Sunday in March and the first Sunday in November.
CST, CDT, CT Central Standard (-0600), Central Daylight (-0500), and Central Time, with the same rules for daylight time as ET.
MST, MDT, MT Mountain Standard (-0700), Mountain Daylight (-0600), and Mountain Time.
PST, PDT, PT Pacific Standard (-0800), Pacific Daylight (-0700), and Pacific Time.

Here are some examples: