If someone keeps a special day, they do it for the Lord. If someone eats, they thank God. If someone does not eat, they still do it for the Lord and thank God.
He who observes a special day does so to the Lord; he who eats does so to the Lord, for he gives thanks to God; and he who abstains does so to the Lord and gives thanks to God.
KJV
He that regardeth the day, regardeth [it] unto the Lord; and he that regardeth not the day, to the Lord he doth not regard [it]. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks.
ASV
He that regardeth the day, regardeth it unto the Lord: and he that eateth, eateth unto the Lord, for he giveth God thanks; and he that eateth not, unto the Lord he eateth not, and giveth God thanks.