The name day for Ilia is observed on August 2 in Poland.
Ilia is recognized globally, chiefly in Eastern Europe, as the Slavic masculine form of the Biblical name Elijah. Historically, this name meaning "My God is the Lord" spread widely through Orthodox Christian traditions. The name is overwhelmingly categorized as male, reflecting strong cultural continuity in Russia, Ukraine, and related regions. Ilia carries a dignified and elegant mood, projecting established strength and traditional values. While less common in the USA, it signifies deep family heritage for those who bear it. Its linguistic origin roots it firmly in ancient religious texts.
| Country | Day | Month | Names |
 Spain | 3 | January | Daniel, Genova, Genoveva, Jennifer, Florencio, Prisciliano |
 Austria | 5 | January | Emilia, Johann |
 Poland | 5 | January | Edward, Emilian, Emiliusz, Hanna, Symeon, Szymon, Telesfor, Włościbor |
| Spain | 5 | January | Amada, Simón, Simona, Emiliana |
 Sweden | 1 | February | Max, Maximilian |
 Italy | 9 | February | Girolamo Emiliani |
 Lithuania | 14 | February | Liliana, Saile, Saulius, Valentinas |
| Poland | 14 | February | Adolf, Adolfa, Adolfina, Alf, Cyryl, Dobiesława, Dobisława, Józef, Józefa, Konrad, Konrada, Krystyna, Lilian, Liliana, Mikołaj, Niemir, Niemira, Walenty, Zenon, Zenona |
 Czechia | 25 | February | Liliana |
 Latvia | 10 | March | Adrians, Kira, Laimrota, Liliana, Silvija |
| Spain | 12 | March | Josefina, Maximiliano, Fina |
| Italy | 13 | March | Massimiliano |
| Austria | 21 | March | Axel, Christian, Emilia |
| Spain | 27 | March | Ruperto, Lilia, Alejandro |
| Spain | 5 | April | Emilia, Vicente Ferrer |
| Sweden | 9 | April | Ottilia, Otto |
| Latvia | 30 | April | Liana, Liliana, Lilija, Linda |
| Austria | 10 | May | Gordian, Isidor, Liliana |
 USA | 10 | May | Cormac, Cormick, Gordon, Job, Joby, Jobina, Max, Maximilian, Maximus, Maxine, Maxwell |
 Finland | 19 | May | Emilia, Emma, Mila, Milena, Amalia, Emmi, Milja, Milka, Milla, Amelia |
 Estonia | 20 | May | Liilia, Lilian, Liili, Lille, Lilli, Lilja |
| Finland | 20 | May | Lilian, Lilja, Karoliina, Lila, Lili, Lilli, Lilia |
| Poland | 23 | May | Budziwoj, Dezyderiusz, Dezydery, Emilia, Iwona, Jan, Leontyna, Michał, Symeon |
| Spain | 24 | May | Rocío, Susana, Auxiliadora, Providencia, Ester |
 Slovakia | 28 | May | Viliam |
| USA | 28 | May | Bevan, Bevis, Emil, Emiliano, Emilio, Faron, Ferrin, Ferron |
| Czechia | 29 | May | Maxmilián |
| Poland | 29 | May | Bogusława, Maksymilian, Maria Magdalena, Teodor, Teodozja |
 Bulgaria | 30 | May | Emiliya, Emil, Emilia, Emilian, Emiliana |
 Hungary | 3 | June | Klotild, Cecília |
 Romania | 3 | June | Claudie, Dionisie, Ipatie, Luchilian, Paul |
| USA | 14 | June | Basil, Basilia, Jaren, Jaron, Jarron, Vasily |
| Poland | 24 | June | Dan, Danisz, Danuta, Emilia, Jan, Wilhelm |
| Poland | 30 | June | Alpinian, Ciechosława, Cyryl, Emilia, Lucyna, Marcjal |
| Austria | 8 | July | Amalia, Edgar, Kilian |
| Poland | 8 | July | Adrian, Adrianna, Chwalimir, Edgar, Elżbieta, Eugeniusz, Kilian, Prokop, Wirginia |
| USA | 8 | July | Aquila, Aquilina, Easton, Kilian |
| Bulgaria | 18 | July | Emil, Emilian, Emilia, Emiliyana |
 Greece | 18 | July | Emilianos, Emily |
| Romania | 18 | July | Emilian, Pamvo |
| Spain | 18 | July | Emiliano, Federico, Luz |
| Hungary | 19 | July | Emília |
| Hungary | 27 | July | Olga, Liliána |
| USA | 27 | July | Joy, Joyce, Lila, Lilac, Liliana, Lillian, Lillie, Lilly, Lily |
| Poland | 31 | July | Beatus, Demokryt, Emilian, Ernesta, Ernestyna, Helena, Iga, Ignacja, Ignacy, Justyn, Ludomir, Żegota |
| Greece | 4 | August | Maximilian |
| Bulgaria | 8 | August | Emil, Emilian, Emiliya, Emilia, Trendafil |
| Poland | 8 | August | Cyprian, Cyriak, Cyryl, Emil, Emilian, Emiliusz, Niezamysł, Olech, Sylwiusz |
| Romania | 8 | August | Emilian, Miron |
 Ukraine | 8 | August | Amelia, Amilian, Emil, Emily, Fedir, Theodore, Leonid |
| Austria | 14 | August | Maximilian, Meinhard |
| USA | 18 | August | Aileen, Eileen, Elaina, Elaine, Eleanor, Elena, Eliana, Ella, Elle, Ellen, Ellie, Helen, Helena, Iliana, Lena, Leonora, Nell, Nellie, Nelly |
| Poland | 19 | August | Bolesław, Emilia, Jan, Julian, Juliusz, Ludwik, Piotr, Sebald |
| Austria | 21 | August | Maximilian, Pius |
| Poland | 21 | August | Adolf, Adolfa, Adolfina, Alf, Bernard, Emilian, Filipina, Franciszek, Joanna, Kazimiera, Męcimir |
| Poland | 4 | September | Agatonik, Ida, Lilianna, Rościgniew, Róża, Rozalia |
| Sweden | 6 | September | Lilian, Lilly |
| Greece | 13 | September | Kornilios, Kornilia, Aristeides |
| Poland | 11 | October | Aldona, Brunon, Burchard, Dobromiła, Emil, Emilian, Emiliusz, Germanik, Maria, Marian, Placydia |
| Austria | 12 | October | Edwin, Gottfried, Maximilian |
 Denmark | 12 | October | Maximilian |
 Germany | 12 | October | Maximilian |
| Poland | 12 | October | Cyriak, Eustachiusz, Eustachy, Grzymisław, Maksymilian, Ostap, Salwin, Serafin, Witold, Witołd, Witolda |
| Slovakia | 12 | October | Maximilián |
| Lithuania | 21 | October | Gilinda, Hiliaras, Raitvilas, Ursule |
| Bulgaria | 8 | November | Angel, Angelina, Arhangel, Gavrail, Gavril, Emil, Emilia, Emiliana, Mihaela, Mihail, Ognyan, Ognyana, Plamen, Plamena, Rada, Radka, Radko, Rafail, Raia, Raika, Raina, Rangel, Emiliya, Emiliyana, Emiliyan, Lina, Mila, Milen, Milyo, Mihaela, Mihail, Radivoy, Radoslav, Radoslava, Radostin, Radostina, Raiko, Raycho, Rangel, Rafail, Raya, Rusi |
| Sweden | 14 | November | Emil, Emilia |
| Austria | 22 | November | Cäcilia, Salvator |
| Denmark | 22 | November | Cecilia |
| Estonia | 22 | November | Cecilia, Säsil, Silja, Silje, Sille |
| Finland | 22 | November | Selja, Silja, Seela, Cecilia |
| Greece | 22 | November | Filimonos, Cecilia |
| Hungary | 22 | November | Cecília |
| Italy | 22 | November | Cecilia |
| Slovakia | 22 | November | Cecília |
| Spain | 22 | November | Cecilia |
| Sweden | 22 | November | Cecilia, Sissela |
| USA | 22 | November | Abbey, Abbie, Abby, Abigail, Cecelia, Cecil, Cecilia, Cecily, Cecyl, Celia, Gael, Gail, Galen, Gay, Gayle, Philemon, Philo, Shayla, Sheila |
| Poland | 24 | November | Dobrosław, Emilia, Emma, Flora, Franciszek, Gerard, Gerarda, Gerhard, Jan, Mina, Pęcisław, Protazy |
| Slovakia | 24 | November | Emília |
| Greece | 26 | November | Stilianos, Stella, Stelios |
| Poland | 27 | November | Damazy, Dominik, Leonard, Maksymilian, Oda, Stojgniew, Walery, Wirgiliusz |
| USA | 27 | November | Fergus, Farrel, Farrell, Ferrell, Ginger, Virgil, Virgilia, Virginia |
| Poland | 6 | December | Dionizja, Emilian, Jarema, Jarogniew, Mikołaj |
| USA | 10 | December | Emely, Emilee, Emilia, Emilie, Emily, Eula, Eulalia, Ula |
| Slovakia | 12 | December | Otília |
| Austria | 13 | December | Jodok, Lucia, Odilia |
| Hungary | 13 | December | Luca, Otília |