1.\" 2.\" @(#)zdump.8 8.1 3.\" $FreeBSD: src/usr.sbin/zic/zdump.8,v 1.7.2.2 2003/03/11 22:31:35 trhodes Exp $ 4.\" $DragonFly: src/usr.sbin/zic/zdump.8,v 1.3 2008/10/19 20:15:58 swildner Exp $ 5.\" 6.Dd October 19, 2008 7.Dt ZDUMP 8 8.Os 9.Sh NAME 10.Nm zdump 11.Nd timezone dumper 12.Sh SYNOPSIS 13.Nm 14.Op Fl v 15.Op Fl c Bo Ar loyear Ns , Bc Ns Ar hiyear 16.Op Ar zonename ... 17.Sh DESCRIPTION 18The 19.Nm 20utility prints the current time in each 21.Ar zonename 22named on the command line. 23.Pp 24The following options are available: 25.Bl -tag -width indent 26.It Fl v 27For each 28.Ar zonename 29on the command line, 30print the time at the lowest possible time value, 31the time one day after the lowest possible time value, 32the times both one second before and exactly at 33each detected time discontinuity, 34the time at one day less than the highest possible time value, 35and the time at the highest possible time value, 36Each line ends with 37.Em isdst=1 38if the given time is Daylight Saving Time or 39.Em isdst=0 40otherwise. 41.It Fl c Bo Ar loyear Ns , Bc Ns Ar hiyear 42Cut off verbose output near the start of the given year(s). 43By default, 44the program cuts off verbose output near the starts of the years -500 and 2500. 45.El 46.Sh LIMITATIONS 47The 48.Fl v 49option may not be used on systems with floating-point 50.Vt time_t 51values that are neither float nor double. 52.Pp 53Time discontinuities are found by sampling the results returned by 54.Xr localtime 3 55at twelve-hour intervals. 56This works in all real-world cases; 57one can construct artificial time zones for which this fails. 58.Sh "SEE ALSO" 59.Xr ctime 3 , 60.Xr tzfile 5 , 61.Xr zic 8 62