There are two ideologically correct methods to change the default system time zone on Solaris 11:

Using nsladm:

Install the nls-administration package if it is not already available:
# pkg install nls-administration

List the available time zones:
# nlsadm list-timezone

Finaly, set the correct time zone:
# nlsadm set-timezone timezone # nsladm set-timezone Canada/Eastern

Updating the timezone:default SMF property timezone/localtime:

# svccfg -s timezone:default setprop timezone/localtime = astring: Canada/Eastern # svcadm refresh timezone:default