Mahalo (thanks in Hawaiian) for asking this question. The three days refer to the day He died, the day He arose, and the day in between. The Jewish day goes from evening to evening. So the first day would have been Thursday evening to Friday evening, the day Jesus suffered and died. Jesus’ last words were, “It is Finished.” The finishing of the suffering part.
After Jesus died, they placed His body in a tomb, but Jesus went to what is called Abraham’s Bosom. Abraham’s Bosom was a heavenly-type place (But not heaven itself) for all believers who died before Jesus died. Jesus went there to escort them all to heaven. Abraham’s bosom was separated from hell (Not the lake of fire) by a great barrier. Apparently, the two sides could see and communicate with each other. We know this because of the story in Luke 16:19-31. Please read this story and believe.
Therefore, during the three days between His death and resurrection, Jesus released His people from the holding (Abraham’s Bosom) area and settled them in heaven. Now, when believers die, their bodies are buried, but they go directly to heaven.
If you have not yet accepted Jesus as your Lord and Savior, remember that the people who die without believing in Jesus still go to hell. Hell still can see, the now empty Abraham’s Bosom, but are stuck to remembering all the chances to choose the right path but did not. If you do not know how to choose the right path, Please ASK!
“Remember, if you don’t understand, ask!”