The first twin, a baby boy named Joaquin, was born on Sunday night at 11:58.
His younger twin sister, Aitana, arrived 18 minutes later, at 12:16 a.m., weighing 2.2 kg. His twin sister was breech and had to be delivered via C-section.
The hospital wrote on Facebook that it was "honored to play a significant role in this 2018 New Year delivery of baby twins" and thanked the "dedicated" hospital staff.
Their parents say the babies came about a month early with the due date being in late January.
But these twins are going to miss out on both as they were born in different years, months and days; even though they are just twenty minutes apart. However, at 7 p.m. EST on New Year's Eve, their mother Maria went into premature labor.
Maria Flores was originally due to give birth on January 27, but her bundles of joy decided to make an early arrival.
It appears the first baby born in Kern County was in Delano. New Years Day in Delano, Calif.
The twins have been gifted over $3,000 of baby supplies by Delano Regional Medical Centre.
And there was another such twin birth the year before also in San Diego, according to the Daily Mail. "The whole family feels humbled and blessed and excited", the spokesman shared.
While an incident like this is extremely uncommon, a year ago, four such twin births were recorded in the USA - in Georgia, Utah, Arizona and San Diego in California.
It was therefore quite a shock when she went into labour on New Year's Eve.