When attempting to use the date command with an ISO-8601 [1] formatted combined time and date, BusyBox does not accept the standard 'T' delimiter. Date from coreutils does. I built this version locally because I was cross-compiling for an embedded PowerPC Linux target. The issue is present on both targets. > kaltendorf@kaltendorf-VirtualBox:~/bb/busybox-1.23.2$ ./busybox > BusyBox v1.23.2 (2015-03-26 14:01:55 EDT) multi-call binary. > BusyBox is copyrighted by many authors between 1998-2012. > Licensed under GPLv2. See source distribution for detailed > copyright notices. > > <snip> > > kaltendorf@kaltendorf-VirtualBox:~/bb/busybox-1.23.2$ sudo ./busybox date --utc --set="2015-04-19T12:59:23+00:00" date: invalid date '2015-04-19T12:59:23+00:00' > kaltendorf@kaltendorf-VirtualBox:~/bb/busybox-1.23.2$ sudo ./busybox date --utc --set="2015-04-19 12:59:23+00:00" Sun Apr 19 12:59:00 UTC 2015 > kaltendorf@kaltendorf-VirtualBox:~/bb/busybox-1.23.2$ sudo date --utc --set="2015-04-19 12:59:23+00:00" Sun Apr 19 12:59:23 UTC 2015 > kaltendorf@kaltendorf-VirtualBox:~/bb/busybox-1.23.2$ sudo date --utc --set="2015-04-19T12:59:23+00:00" Sun Apr 19 12:59:23 UTC 2015 [1]: http://en.wikipedia.org/wiki/ISO_8601#Combined_date_and_time_representations