The name day associated with Iva in Czechia is observed on December 1st.
Iva is a concise feminine name primarily rooted in Slavic languages, where it often signifies the willow tree, associating it with nature and resilience. Historically, its usage in the United States peaked around the turn of the 20th century, where it served as a simple, yet sturdy choice. Today, the name maintains a profile of sophisticated simplicity, lending it an elegant and quietly strong mood. It is globally recognized as distinctly female, particularly across Eastern and Central Europe. Though rare in modern US rankings, Iva offers a streamlined option for those seeking a vintage name with powerful, natural undertones.
| Country | Day | Month | Names |
 Bulgaria | 7 | January | Ivan, Ivaylo, Ivanka, Vanio, Vania, Encho, Enio, Zhan, Zhana, Ivayla, Ivelin, Ivelina, Ivet, Ivo, Yoan, Ioan, Ioana, Yonka, Yonko, Yoncho, Yoto, Kaloyan, Kaloian |
 Greece | 7 | January | Ioannis, Giannis, Gianna, John, Jeannette, Ivana, Prodromos |
 Latvia | 8 | January | Erhads, Gatis, Gundabis, Ivanda |
 Croatia | 12 | January | Arkadije, Živana, Ernest |
 Norway | 22 | January | Ivan, Vanja |
| Latvia | 29 | January | Aivars, Valerijs |
 Lithuania | 29 | January | Aivaras, Girkantas, Valerijus, Zibute |
| Croatia | 31 | January | Ivan, Marcela, Julije |
| Norway | 31 | January | Idun, Ivar |
 Sweden | 31 | January | Ivar, Joar |
| Latvia | 27 | February | Andra, Daiva, Liva, Livija |
| Latvia | 1 | March | Ikars, Ilgvars, Ilvars, Ivars |
| Croatia | 8 | March | Pačista, Ivan |
| Latvia | 12 | March | Aija, Aiva, Aivis, Ausmins, Gregors |
| Croatia | 27 | March | Ivan Damašć., Rupert, Lidija, Lada |
 Czechia | 4 | April | Ivana |
| Croatia | 7 | April | Ivan de la Salle, Herman, Epifan |
| Lithuania | 14 | April | Justinas, Vaisvyde, Vaiva, Valerijonas, Visvaldas |
 Hungary | 20 | April | Tivadar |
| Croatia | 10 | May | Ivan Merz, Gospa Trsat |
 Estonia | 11 | May | Liivar, Liivo, Leevo |
| Latvia | 14 | May | Aiva, Duda, Elfa, Krisjanis, Kriss |
| Croatia | 16 | May | Ivan Nepomuk, Andrija Bobola, Nenad |
| Croatia | 18 | May | Ivan I. papa, Venancije, Srecko |
 USA | 19 | May | Dumont, Duncan, Dunstan, Indigo, Ivar, Ives, Wright, Yves |
| Sweden | 24 | May | Ivan, Vanja |
 Finland | 29 | May | Oiva, Oliver, Olivia, Livia |
| Croatia | 30 | May | Ivana Arška |
| Estonia | 2 | June | Viivia, Vivian, Viiva, Viive, Viivi, Viivika, Veevi |
 Spain | 3 | June | Oliva, Kevin, Cecilio, Davino, Clotilde, Luciniano |
| Croatia | 10 | June | Margareta, Dijana, Bl. Ivan Dominici |
| Croatia | 12 | June | Ivan Fakundo, Bosiljko, Nino |
| Latvia | 14 | June | Kitija, Klitija, Saiva, Sentis, Tija |
| Finland | 16 | June | Päivi, Päivikki, Päivä |
| Lithuania | 18 | June | Arnulfas, Ginbutas, Marina, Vaiva |
| Croatia | 22 | June | Ivan Fisher, Toma More |
| Croatia | 24 | June | Rodenje Ivana Krstitelja |
| Hungary | 24 | June | Iván |
| Spain | 24 | June | Juan, Juana, Ivana, Joan, Jon, Iván, Jean |
 Ukraine | 24 | June | Bohuslav, Bohuslava, Boris, Boryslav, Boryslava, Slavko, Slavka, Ivan, John, Yvonna, Jean, Joan, Johanna |
| USA | 24 | June | Hans, Giovanna, Giovanni, Ian, Ivan, Jan, Jana, Jean, Jeanette, Jeannette, Johan, John, Johnnie, Johnny, Juan, Juana, Juanita, Sean, Shana, Shane, Shanna, Yancy |
| Czechia | 25 | June | Ivan |
| Croatia | 26 | June | Ivan, Pavao, Vigilije, Zoran |
| Estonia | 26 | June | Manivald, Vanevald, Vane, Vaane, Vaano, Vaino |
| Latvia | 30 | June | Mareks, Talis, Talivaldis |
| USA | 6 | July | Godiva, Isaiah, Isaias, Isiah, Jamaal, Jamal, Jamel, Jamil, Pallas, Shea, Shyanne |
| Norway | 8 | July | Sunniva, Synne, Synnøve |
 Slovakia | 8 | July | Ivan |
| Spain | 22 | July | Teófila, Zoraida, Magdalena, Zaida, Primitiva |
| Croatia | 23 | July | Brigita Švedska, Ivan Cassian, Slobodan |
| Croatia | 4 | August | Ivan M. Vianney, Ivica, Tertulijan |
| Lithuania | 6 | August | Bylotas, Daiva, Karolina |
| Croatia | 13 | August | Poncijan, Hipolit, Ivan Berchmans |
| Croatia | 19 | August | Ivan Eudes |
| Estonia | 22 | August | Iivo, Ivo, Ivar, Ivari, Ivalo |
| Finland | 22 | August | Iivari, Iivo |
| USA | 26 | August | Percival, Percy, Travis, Trevis, Trevon, Trevor |
| Croatia | 29 | August | Glavosijek Ivana Krstitelja, Sabina R. |
| Croatia | 13 | September | Ivan Zlatousti, Ljubo |
| Croatia | 18 | September | Ivan Macias, J. Kupert., Irena |
| Latvia | 23 | September | Ivanda, Omula, Vanda, Veneranda |
| Croatia | 9 | October | Ljudevit Bertran, Dionizije, Ivan Leon |
| Croatia | 23 | October | Ivan Kapistran, Borislav, Severin |
| Latvia | 26 | October | Amanda, Kaiva |
| Croatia | 9 | November | Ivan Lateranski |
| Hungary | 9 | November | Tivadar |
| USA | 9 | November | Orestes, Sullivan, Vaughan, Vaughn |
| Croatia | 14 | November | Nikola Tavelic, Ivan Trogirski |
| Croatia | 4 | December | Ivan Damašcanski, Barbara |
| Croatia | 11 | December | Ivana Franciska Ch. |
| Estonia | 12 | December | Aivar, Aiver, Aivo |
| Croatia | 13 | December | Ivan, Krševan |
| Croatia | 22 | December | Ivan Kentijski, Viktorija |
| Croatia | 26 | December | Ivan ev., Ivo, Janko |
| Slovakia | 28 | December | Ivana |