1.\" $NetBSD: zdump.8,v 1.10 2013/07/17 20:13:04 christos Exp $ 2.Dd July 17, 2013 3.Dt ZDUMP 8 4.Os 5.Sh NAME 6.Nm zdump 7.Nd time zone dumper 8.Sh SYNOPSIS 9.Nm zdump 10.Op Fl \-version 11.Op Fl v 12.Op Fl V 13.Op Fl c Ar [loyear,]highyear 14.Op Ar zonename ... 15.Nm zdump 16.Fl t 17.Ar [loyear,]highyear 18.Op Ar zonename ... 19.Sh DESCRIPTION 20.Nm 21prints the current time in each 22.Ar zonename 23named on the command line. 24.Pp 25These options are available: 26.Bl -tag -width XXXXXXXXX -compact 27.It Fl \-version 28Output version information and exit. 29.It Fl v 30For each 31.Ar zonename 32on the command line, 33print the time at the lowest possible time value, 34the time one day after the lowest possible time value, 35the times both one second before and exactly at 36each detected time discontinuity, 37the time at one day less than the highest possible time value, 38and the time at the highest possible time value, 39Each line ends with 40.Dl isdst=1 41if the given time is Daylight Saving Time or 42.Dl isdst=0 43otherwise. 44.It Fl c Ar [loyear,]highyear 45Cut off the verbose output near the start of the given year(s). 46By default, 47the program cuts off verbose output near the starts of the years \-500 and 2500. 48.It Fl t Ar [loyear,]highyear 49Cut off verbose output at the start of the given time(s), 50given in decimal seconds since 1970-01-01 00:00:00 UTC. 51.It Fl V 52Like 53.Fl v , 54except omit the times relative to the extreme time values. 55This generates output that is easier to compare to that of 56implementations with different time representations. 57.El 58.Sh LIMITATIONS 59The 60.Fl v 61and 62.Fl V 63options may not be used on systems with floating-point time_t values 64that are neither float nor double. 65.Pp 66Time discontinuities are found by sampling the results returned by localtime 67at twelve-hour intervals. 68This works in all real-world cases; 69one can construct artificial time zones for which this fails. 70.Sh SEE ALSO 71.Xr ctime 3 , 72.Xr tzfile 5 , 73.Xr zic 8 74.\" @(#)zdump.8 8.2 75.\" This file is in the public domain, so clarified as of 76.\" 2009-05-17 by Arthur David Olson. 77