Writer Blanka Lipinska revealed that the shot where lead actor Michele Morrone spits into the private parts of the actress playing Laura during sexual intercourse was cut from prior versions of the film and was only re-instated after she asked for it to be put back in. She said it was "a very popular gesture in Poland" for couples.
The film-makers went to great lengths to make the sex scenes authentic. The film-makers wanted the audience to hear the whispers and heavy breath of the actors and see their sweat and passion. They made the camera non-intrusive and invisible for the two actors so that they could act out the scene at length in several long takes. On-set crew was reduced to a minimum. The scenes turned out to be so convincing that several viewers mistakenly thought the lead actors really had sex on set and the actors had to personally shoot down the speculation.
Before he got the script for this movie, Michele Morrone had given up on his film and television career. He was newly divorced, broke, severely depressed, and working as a gardener in a tiny northern Italian village. After five months toiling alongside cows and chickens, he got a call from his agent saying a team of Polish filmmakers wanted to offer him the lead role of an Italian mafia boss. Morrone said he called his gardening boss said, "I'm not coming in today. My stomach doesn't feel good," and boarded a plane to Poland.
Asked what was the most difficult scene to shoot in the movie, Michele Morrone said, "It was the blowjob scene. It was really difficult for me because I got on set and I met this girl - Hi, nice to meet you. And after two minutes that I met her, she starts blowing me. I had a fake strap-on penis, and she was blowing that. It was awkward but it was funny because she was blowing the fake dick. I could't just act the part because as soon as she was starting, I could hear people around me giggling. And I was like - What the ficky, just be serious."
Comparing this film favorably to 50 Shades of Grey (2015), lead star Michele Morrone pointed out that this film was more sexually explicit that 50 Shades which he said was "too clean" and not "rough or passionate" enough. He stated that, unlike compromises made to bring 50 Shades to the screen, the audience will be able to see that this movie is exactly what they read and imagined in the novel 365 days. Several film critics comparing the two films have acknowledged the increased level of explicitness in this film compared to 50 Shades.