1ALEVT-DATE(1)                    Teletext time                   ALEVT-DATE(1)
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NAME

6       alevt-date - display/set time received via Teletext
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SYNOPSIS

10       alevt-date [options]
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DESCRIPTION

14       alevt-date displays the time received from a Teletext source.  It can
15       be used to set the system time.  The date is not interpreted (not even
16       transmitted on most channels).  So it allows only adjustment of +/-12
17       hours.  The default allowed adjustment is limited to +/-2 hours (use
18       -delta to change).  Without the -set option it just displays the date
19       in the format of the date(1) command.
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OPTIONS

23       A summary of options is included below.
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25       -set              Set system time from time received via Teletext.
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27       -delta seconds    Maximum allowed adjustment made to the system time.
28                         The default is 7200 seconds (2 hours) and the maximum
29                         that may be given is 12 hours.
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31       -format string    Format string to used to print the time.  Look at
32                         strftime(3) for possible control sequences.
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34       -vbi device       Use the given device name.  Default: /dev/vbi,
35                         /dev/vbi0, /dev/video0, /dev/dvb/adapter0/demux0
36                         tried in this order.
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38       -timeout seconds  If the time can't be detected in seconds, the program
39                         is terminated with a SIGALRM.
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41       -progname name    Specifies the program name if using the DVB inter‐
42                         face.
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44       -pid pid          Specifies the teletext PID if using the DVB inter‐
45                         face.
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47       --help            Show summary of options.
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49       --version         Show version of program.
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51       Before starting this program, you have to set the TV channel with an‐
52       other program like xawtv of set-tv.
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54       Note: This program does not set the battery backed up clock of your
55       computer.  clock -w will do this.
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57       The -progname or -pid option specifies the program or teletext PID if
58       using the DVB interface.
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60       If neither of these two options is used, alevt outputs informations
61       about the currently accessible streams and uses the first of these PIDs
62       as default. This output contains the PIDs and names that can be used as
63       an input for the -progname or -pid option in the context of the cur‐
64       rently chosen TV channel.
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FILES

68       /dev/vbi*
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70       /dev/dvb/adapter*/demux*
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SEE ALSO

74       alevt(1x), alevt-cap(1), strftime(3), date(1), clock(8).
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BUGS

78       This program is just a toy.  The time transmitted by the TV stations is
79       more than inaccurate.  Some are within a few seconds of your local time
80       reference but others are more then 15 minutes off.  You've been warned.
81       (And don't assume the pkt8/30 time is better.  It's even worse.)
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83       Bug reports to <https://gitlab.com/alevt/alevt>.
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87LINUX                                1.8.1                       ALEVT-DATE(1)
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