ntpd-setwait is very small program that ensures time is synchronized before ntpd daemon can be started. This is not replacement for ntpd, you still need ntpd installed, it's just ntpd will not be started until ntpd-setwait sets system time from ntp server.

Program is designed for embedded systems which might not have RTC and back up battery, which results in time reset each time board reboots or power is cut off and internet may or may not be available at time of boot up. Desktop and server users rather won't find it usefull.


Well, openntpd has -s argument, which will cause system time to be set immediately when openntpd starts. Problem is, that openntpd after 15 seconds (in case no internet) will forfeit request to set system time, and will fork into background leaving you stuck in 1970 making little forward jumps with adjtime(), which will take forever to get to present date.

This is where ntpd-setwait comes in. It will hang in infinite loop, waiting for internet, when that is available, it reads current time from ntp server, sets current system time. If all steps succeds ntpd-setwait starts ntpd of your choosing to keep the time synchronized from now on.


Description and usage can be found in manual page.


None, just unix system and any ntpd daemon.

Compile and install

Program uses autotools, so instalation is very easy:

$ ./
$ ./configure
$ make
# make install can be ommited if you have downloaded tarball. That script must be called only if you cloned sources from git repository.


Program is licensed under BSD 2-clause license. See LICENSE file for details.


Michał Łyszczek

See also