If your openwrt is not changing to DST this year, try this TZ as settings "CET-1CEST,M3.4.0,M10.4.0/3".
Update your /etc/config/system file as this:
config 'system'
option 'hostname' 'gate1'
option 'zonename' 'Europe/Bratislava'
option 'timezone' 'CET-1CEST,M3.4.0,M10.4.0/3'
option 'cronloglevel' '8'
option 'conloglevel' '7'
and /etc/TZ
CET-1CEST,M3.4.0,M10.4.0/3Finally run /etc/init.d/sysntpd reload.
Enjoy!