What is the maximum --seconds time that can be set in a blocking rule in iptables on OpenWRT?

Question

iptables

Tell me what the maximum value can be set in the rule: -m conntrack --ctstate NEW -m recent --name BLOCK --rcheck --seconds 3600 -j DROP
You need to block IP for several days. But I'm not sure that my router will pull such large numbers (several days in seconds).
Or can you specify --hours ?