Erma's name day is observed on April 7 in the United States.
The feminine name Erma boasts a Germanic origin, often linked to concepts meaning “whole” or “universal,” suggesting completeness. In the United States, Erma enjoyed its greatest prominence during the late 19th and early 20th centuries, consistently appearing in the top ranks of female names. Today, it is valued as a classic, vintage choice, having experienced a significant drop in usage after the 1940s. Its mood is characterized as sturdy, traditional, and dependable, lending it a dignified yet straightforward tone. As an exclusively female name worldwide, Erma maintains a strong identity rooted in historical reliability.
| Country | Day | Month | Names |
 Norway | 29 | January | Herdis, Hermann, Hermod |
 Lithuania | 25 | March | Bermantas, Kantrimas, Normantas, Normante |
 Croatia | 7 | April | Ivan de la Salle, Herman, Epifan |
 Czechia | 7 | April | Heřman, Hermína |
 Hungary | 7 | April | Herman |
| Lithuania | 7 | April | Donata, Hermanas, Kantaute, Minvydas |
 Poland | 7 | April | Donat, Donata, Epifaniusz, Hegezyp, Herman, Przecław, Rufin |
 Latvia | 11 | April | Hermanis, Ira, Irida, Vilmars |
| Poland | 11 | April | Filip, Herman, Jaromir, Leon, Marek |
 Spain | 2 | May | Germán, Araceli, Atanasio, Vindemial, Exuperio, Zoé, Mafalda |
| Croatia | 9 | May | Herman, Mirna, Beato, Kristofor |
| Spain | 9 | May | Gregorio, Hermas, Geroncio |
 Ukraine | 12 | May | Herman |
 Austria | 28 | May | Germanius, Wilhelm |
| Croatia | 28 | May | German |
 France | 28 | May | Germain |
| Poland | 28 | May | Augustyn, German, Jaromir, Priam, Wiktor, Wiktoriusz, Wilhelm, Wrócimir |
| Spain | 28 | May | Agustín, Bernardo, Emilio, Germán |
| Poland | 13 | June | Antoni, Chociemir, Herman, Lucjan, Maria Magdalena, Tobiasz |
| France | 15 | June | Germaine |
 Italy | 15 | June | Germana Cousin |
 USA | 15 | June | Alice, Alicia, Alisa, Alisha, Alison, Alissa, Allie, Allison, Allyson, Alyce, Alyse, Alysha, Alysia, Alyson, Alyssa, German, Germain, Germaine, Jermaine, Vidal, Vito |
 Greece | 28 | June | Germanos |
| Spain | 7 | July | Fermín, Roberto, Odón, Germano, Peregrino |
 Estonia | 12 | July | Hermann, Herman, Armand, Hermo, Härmo, Härm, Härmel |
 Finland | 12 | July | Herkko, Hermanni, Herman |
 Sweden | 12 | July | Herman, Hermine |
| USA | 16 | July | Carmel, Carmela, Carmelo, Carmen, Shelby, Sherman, Sherwood |
| Estonia | 30 | July | Kerman, Kermo, Roland |
| Austria | 31 | July | Hermann, Ignatius, Justinus |
 Denmark | 31 | July | Germanus |
| Denmark | 11 | August | Herman |
| Poland | 11 | August | Aleksander, Herman, Ligia, Lukrecja, Włodzimierz, Włodziwoj, Zula, Zuzanna |
| Austria | 24 | September | Gerhard, Hermann, Rupert, Virgil |
| France | 25 | September | Hermann |
| Poland | 10 | October | Franciszek, German, Kalistrat, Lutomir, Paulin, Tomił |
| Lithuania | 11 | October | Daugvyde, Germanas, Rimdaugas, Zina, Zinaida |
| Poland | 11 | October | Aldona, Brunon, Burchard, Dobromiła, Emil, Emilian, Emiliusz, Germanik, Maria, Marian, Placydia |
| Croatia | 30 | October | Marcel, Marojko, Lukan, German |
| Italy | 30 | October | Germano |
| Greece | 4 | November | Ermaios |