Ilo's name day is November 18 in Estonia.
The name Ilo is a rare and distinctive choice globally, with its primary cultural foothold in Estonia. It is a unisex name characterized by a soft, melodic, and playful mood that evokes feelings of joy. The name is rooted in the Estonian language and is not widely used in the United States, remaining quite uncommon in international registries. Its aesthetic is minimalist and modern, providing a lighthearted vibe that appeals to those looking for non-traditional naming options. As a versatile identifier, it is neither exclusively masculine nor feminine, allowing for broad personal interpretation.
| Country | Day | Month | Names |
 France | 4 | January | Odilon |
 Greece | 13 | January | Ermilos |
 Czechia | 20 | January | Ilona |
 Slovakia | 23 | January | Miloš |
| Czechia | 25 | January | Miloš |
 Lithuania | 27 | January | Ilona, Jogundas, Jogunde, Natalis, Vytenis |
 Poland | 27 | January | Angelika, Ilona, Jan Chryzostom, Julian, Przybysław |
| Lithuania | 5 | February | Agota, Birute, Gaudvinas, Ilona |
| Czechia | 17 | February | Miloslava |
| Slovakia | 17 | February | Miloslava |
| Greece | 19 | February | Filothei |
 Croatia | 3 | March | Anzelmo, Marin, Kamilo |
 Estonia | 8 | March | Viilup, Viilo, Vilbo, Lepo |
 Latvia | 18 | March | Adelina, Ilona, Razna, Sartite |
| Lithuania | 20 | March | Filomenas, Imgarda, Irma, Tautvile, Zygimantas |
| Estonia | 23 | March | Aksel, Ailo |
| Latvia | 21 | April | Anastasija, Margers, Margonis, Nilola |
 USA | 30 | April | Miles, Milo, Myles, Ryder |
 Bulgaria | 21 | May | Elena, Konstantin, Kosta, Kostadin, Kostadinka, Lenko, Dicho, Lenko, Dinko, Elenko, Eli, Elin, Elka, Ilona, Kojcho, Kostadina, Kostadinko, Kuncho, Stamen, Stanimir, Stanimira, Stanka, Stoil, Stoyan, Stoian, Stoyanka, Trayko, Dinko |
| USA | 1 | June | Brigham, June, Junella, Marilee, Marilou, Marilu, Marilyn, Marylynn |
 Spain | 12 | June | Nazario, Olimpo, Cirilo |
| Spain | 27 | June | Socorro, Zoilo, Ladislao, Anecto, Sansón |
| Lithuania | 5 | July | Butginas, Filomena, Karolina, Mantmile |
| Poland | 5 | July | Antoni, Bartłomiej, Filomena, Jakub, Karolina, Michał, Przybywoj, Szarlota, Wilhelm |
| Spain | 5 | July | Filomena, Filomeno, Zoa |
| Greece | 8 | July | Theofilos, Prokopios |
| Slovakia | 11 | July | Milota |
| Croatia | 14 | July | Kamilo de Lellis, Miroslav |
| Spain | 14 | July | Camila, Vladimiro, Camilo |
| Bulgaria | 20 | July | Iliya, Iliyana, Ilko, Ilina, Ilka, Lilo, Lila |
| Poland | 10 | August | Asteria, Bernard, Bogdan, Borys, Filomena, Laurencjusz, Prochor, Wawrzyniec, Wierzchosław |
| Spain | 11 | August | Clara, Filomena, Susana |
| Estonia | 18 | August | Heleene, Helene, Helena, Elina, Ilona, Helen, Hell, Hella, Helle, Hellen, Helli |
 Hungary | 18 | August | Ilona |
| Lithuania | 18 | August | Gendvile, Ilona, Mantautas, Sailenis, Saulene |
| Poland | 18 | August | Agapit, Bogusława, Bronisław, Bronisz, Helena, Ilona, Klara, Tworzysława |
 Finland | 7 | September | Miro, Arho, Arhippa, Milo |
 Romania | 7 | September | Amfilohie, Simeon, Sozont |
| Spain | 19 | September | Nilo |
| Finland | 9 | October | Ilona |
| Croatia | 8 | November | Gracija Kotorski, Milotislav, Bogdan |
| Greece | 10 | November | Milon, Orion |
| USA | 22 | November | Abbey, Abbie, Abby, Abigail, Cecelia, Cecil, Cecilia, Cecily, Cecyl, Celia, Gael, Gail, Galen, Gay, Gayle, Philemon, Philo, Shayla, Sheila |
| Estonia | 6 | December | Nigulas, Nigul, Nikolai, Niilas, Niilo, Nils, Klaus, Laas, Laus |
| Finland | 6 | December | Niilo, Niko, Niki, Nikolas, Niklas, Nikolai, Niila |
| Romania | 7 | December | Filofteia |
 Austria | 11 | December | Arthur, Damasus, Tassilo |
| Latvia | 14 | December | Auseklis, Dailonis, Gaisma |
| Czechia | 18 | December | Miloslav |
| Slovakia | 27 | December | Filoména |