Why is the 000 days after entry as duration?

Hello, I applied for a X visa in the Chinese embassy in Ireland and I received it. It is valid for 3 months but under duration of each stay it says 000 days after entry. Is that a problem or a mistake. My brother received the same visa and it says the same thing. My dad is coming with us on a normal tourist visa for a week and it says 30 days after entry. I know we have to apply for a temporary residence permit when we get there but will this be a problem? Thanks, Aisha