A "daysman" is an "umpire or arbitrator; a mediator" in its archaic usage, according to the OED. From a 16th century legal source we have, "If neighbors were at variance, they ran not straight to law: Daysmen took up the matter, and cost them not a straw." Or, in another case, "They had some common arbitrators, or dayesmen, in every towne, that made a friendly composition between man and man."
Job lamented, speaking of God, "For He is not a man, as I am, that I should answer Him, and we should come together in judgment. Neither is there any daysman betwixt us, that might lay his hand upon us both." Job 9:32,33 There was a huge gulf between Job and God, like an ant trying to communicate with a man. As I read this I realized what a treasure it is that I do have a daysman! I John 2:1 says, "...we have an advocate with the Father, Jesus Christ the righteous:..." Job in his trials had no one to go between him and God, to take his part, or to explain God to him. We have, in Jesus Christ, both an explanation of God to us and an advocate with God on our behalf - in fact Jesus Christ Himself covers our debts (spiritually speaking). Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need. Hebrews 4:16