Author:	    Dave.Sparks@sisyphus.demon.co.uk (as at 1 Nov 1995)

Requires:   WB 2.04, AmiTCP
Version:    2


RdateTZ is an alternative to utilities such as SynClock, which set the
local clock in accordance with the time obtained by querying the `daytime'
port (13) of a remote host.  RdateTZ improves on SynClock by:

    1	Using the `time' port (37) of the remote host, which returns
	the GMT value of the remote host's clock.  (The `daytime'
	port (13) normally returns the local time at the remote host's
	site, but could return GMT and is not required to identify the
	timezone - see RFC867.)

    2	(Optionally) ignoring a remote host whose clock is too far
	out of step with the local clock (reducing the risk of
	synchronising with a clock which is running fast or slow).

    3	Using datagrams rather than a stream, which allows several
	remote hosts to be queried simultaneously.  The first
	acceptable (see 2 above) reply is used.

    4	Using a file of timezone specifications to set the local clock
	to a specified timezone, allowing for daylight saving time if
	appropriate.  A subset of the XPG3 standard for the TZ
	environment variable is used, which allows the offsets and
	daylight saving time start and end dates of most timezones to
	be encoded.

    5	Setting a value identifying the selected timezone in the TZ
	environment variable, and recording an RFC822-compliant
	timezone identifier in the comment associated with the file
	holding this environment variable.

SetTZ provides a subset of the RdateTZ interface, which allows the local
clock to be set to a specified timezone without changing the GMT value of
the clock.  This can be called each time the machine is rebooted, or in the
early hours of every morning, to switch to or from daylight saving time on
the appropriate dates.	No attempt is made to access any external host.


Changes made in version 2:

	The configuration file has been updated to reflect changes to
	the daylight saving time dates in Europe and Australia, and to
	add rules for Alaska and Hawaii.


This distribution consists of the following files:

    RdateTZ.readme

	This file.  You need not keep it.

    RdateTZ

	The executable file.  This must be copied to a directory on
	your path (for example c: or amitcp:bin).  The name of the
	copy should be RdateTZ or SetTZ (or both, using MakeLink).

    TZ.dat

	The file of timezone specifications.  This must be copied
	to s: (the name s:TZ.dat is built in and cannot be changed).

    RdateTZ.man

	Documentation in AmigaGuide format.  Keep it wherever you like.

You *must* set the environment variable TZ before using RdateTZ or SetTZ.
See RdateTZ.man .

You may need to modify s:TZ.dat, if your timezone is not included or the
value you need to be given to the TZ environment variable is different from
the value in the issued TZ.dat .  See RdateTZ.man .


RdateTZ is free software; you can redistribute it provided that:

    1	no charge is made for the program

    2	all the original files are included intact in the distribution

    3	any additional or alternative files are clearly identified as
	such

RdateTZ is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.