Man pages › Compared with Linux and the BSDs

`zdump(8)` on Solnix vs Linux and the BSDs

On Solnix, zdump is the illumos zdump at /usr/sbin/zdump. Its options match the Linux, FreeBSD and NetBSD pages (-i, -v, -V, -c, -t). The main differences are that zone names are resolved relative to /usr/share/lib/zoneinfo, and that OpenBSD's page documents no -i and no '-' for stdin.

The manual pages

Solnix: zdump(8) from pkgs.solnix.illumos-world-man · illumos.org
Linux: zdump(8) tzdata-2026c
FreeBSD: zdump(8) 15.1-RELEASE
OpenBSD: zdump(8) 8.0
NetBSD: zdump(8) 11.0

What Solnix runs

A default Solnix system runs the illumos zdump at /usr/sbin/zdump. No other variants are shipped. The page's INTERFACE STABILITY section says Uncommitted and states that zdump is not maintained directly by illumos.

Differences

Compared with	Topic	What differs
all four	zoneinfo directory	The Solnix page says a zonename is the name of a time zone database file relative to `/usr/share/lib/zoneinfo.` The Linux, FreeBSD, OpenBSD and NetBSD pages do not name a directory, so check the local path before hardcoding one. Source: Solnix zdump(8) DESCRIPTION; Linux, FreeBSD, OpenBSD, NetBSD zdump(8) DESCRIPTION
OpenBSD	`-i` interval format	Solnix zdump accepts `-i`, which prints an interval-format description of the zone. The OpenBSD page documents no `-i`, and its synopsis is only [`-Vv`] [`-c`] [`-t`]. A script using `-i` may fail on OpenBSD. Source: Solnix zdump(8) -i; OpenBSD zdump(8) SYNOPSIS
OpenBSD	reading TZif data from stdin	On Solnix, a zone name of - is treated as /dev/stdin, so TZif data can be piped in. The OpenBSD page does not document this. Source: Solnix zdump(8) DESCRIPTION; OpenBSD zdump(8) DESCRIPTION
OpenBSD	`-v` output content	Solnix `-v` prints the extreme times, year-boundary times and the times just before and at each discontinuity. Each line ends with isdst=D, which can be positive, zero or negative, and with gmtoff=N when known. OpenBSD `-v` ends lines only with isdst=1 or isdst=0, and the page does not mention gmtoff. Source: Solnix zdump(8) -v; OpenBSD zdump(8) -v
OpenBSD	`--help` and `--version`	Solnix documents `--help` and `--version`. The OpenBSD page documents neither long option. Source: Solnix zdump(8) OPTIONS; OpenBSD zdump(8) SYNOPSIS and options
OpenBSD	`-c` and `-t` cutoff semantics	Solnix `-c` and `-t` are defined with an inclusive lower bound, an exclusive upper bound and a default of `-500`,2500. They apply to interval output. OpenBSD says only that they cut off verbose output near or at the start of the given values. Source: Solnix zdump(8) -c, -t; OpenBSD zdump(8) -c, -t
NetBSD	synopsis forms	The NetBSD synopsis lists `-t` as a separate form, 'zdump `-t` [lotime,]hightime [zonename ...]', and omits `-i` and `--help` from it, although the options section documents both. Solnix lists all options in a single synopsis. Source: NetBSD zdump(8) SYNOPSIS and OPTIONS; Solnix zdump(8) SYNOPSIS
Linux, FreeBSD, NetBSD	same options as Solnix	For `--version`, `--help`, `-i`, `-v`, `-V`, `-c` and `-t`, the option text on the Linux, FreeBSD and NetBSD pages matches Solnix word for word, apart from the argument name highyear/hightime on NetBSD. The only extra Solnix text is the zoneinfo path and the exit status section. Source: Solnix, Linux, FreeBSD and NetBSD zdump(8) OPTIONS
all four	exit status	The Solnix page documents exit status 0 for success and 1 for an error. The Linux, FreeBSD, OpenBSD and NetBSD pages have no exit status section. Source: Solnix zdump(8) EXIT STATUS; Linux, FreeBSD, OpenBSD, NetBSD zdump(8)

Standards

POSIX: zdump is not a POSIX.1-2024 utility.
Solnix: Interface Stability: Uncommitted. The page says zdump is not maintained directly by illumos.

Writing portable scripts

Use only -v, -V, -c and -t in portable scripts: -i and --help are not documented on OpenBSD.
Pass a zone name that resolves under the local zoneinfo directory; do not hardcode a path, since the Solnix page uses /usr/share/lib/zoneinfo.

Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.