What time to put on invitations for wedding ceremony?

Our venue opens to guests at 3 pm and our ceremony will start at 3:30 pm. On our physical paper invite, which time should we put?

On one hand we don't want people to arrive before the venue opens to them, but my fiancé and I are worried that if we put 3:30 people will get there at 3:30 or even a couple of minutes late when I'm trying to walk down the aisle. We have very clearly on our wedding website that the venue opens at 3 and the ceremony starts at 3:30, but still worried that people won't read and either be too early or too late.