example: iptables -A INPUT -p tcp -s 0/0 --sport 513:65535 -d 202.54.1.20 --dport 22 -m state --state NEW,ESTABLISHED -m time --timestart 09:00 --timestop 18:00 --days Mon,Tue,Wed,Thu,Fri -j ACCEPT
So if you add -m time --timestart 09:00 --timestop 18:00 --days Mon,Tue,Wed,Thu,Fri -j ACCEPT to your rule it will be time sensitive.
You will need to specify another rule to kill RELATED,ESTABLISHED traffic.
iptables -t nat -I POSTROUTING -o eth0 -j MASQUERADE -m time --timestart 09:00 --timestop 18:00 --days Mon,Tue,Wed,Thu,Fri -j ACCEPT #if it not between these times the next rule will drop the traffic iptables -t nat -I POSTROUTING -o eth0 -j DROP iptables -A INPUT -m conntrack -j ACCEPT --ctstate RELATED,ESTABLISHED -m time --timestart 09:00 --timestop 18:00 --days Mon,Tue,Wed,Thu,Fri -j ACCEPT iptables -A INPUT -m conntrack -j DROP --ctstate RELATED,ESTABLISHED