According to the 1921 census, Jens Peter was born on 17 Jul 1841. Here is his baptism record from Rørby sogn, Holbæk showing a birth date of 17 Jul 1841, baptism on 15 Aug, and parents named Christian Sorensen and Ane Andersdatter. Here they are in the 1845 census.
Here's Jens Peter and Dorthe's family in the 1870 census after Christian Anton was born.
Plenty of other records available, but I want you to have the pleasure of finding them.
OK, I don't want to throw away other records I've found: Their marriage, 1850 census, 1860 census, 1840 census of parents.