The name Les has an established name day celebration on March 10 within the United States. Additionally, the name is observed on August 30 in Ukraine.
The name Les is strongly recognized in the USA as a concise and familiar masculine short form, often derived from longer names such as Lester or Leslie. Its origin thus stems from mixed English and Scottish roots, referring variously to English place names or elements like “holly patch.” This short form experienced high usage during the mid-20th century, contributing to its current vintage and dependable mood. Les projects a straightforward, unpretentious tone, embodying classic reliability and efficiency. Although Leslie, a source name, is now often unisex, Les retains an overwhelmingly male gender association.
| Country | Day | Month | Names |
 Lithuania | 5 | January | Gaudentas, Telesforas, Vytautas, Vytaute |
 Poland | 5 | January | Edward, Emilian, Emiliusz, Hanna, Symeon, Szymon, Telesfor, Włościbor |
 Spain | 7 | January | Amadeo, Raimundo, Aquiles, Luciano |
| Spain | 24 | January | Francisco de Sales, Tirso, Paz, Feliciano |
 Italy | 25 | January | Francesco di Sales |
| Poland | 1 | March | Albin, Antoni, Antonina, Budzisław, Budzisz, Eudokia, Eudoksja, Ewdokia, Feliks, Herakles, Herkules, Jewdocha, Joanna, Józef, Nikifor, Piotr |
 France | 2 | March | Charles |
 Slovakia | 16 | March | Boleslav |
| Italy | 21 | March | Alessandra |
 Latvia | 21 | March | Benedikts, Boleslavs, Dzelme, Glezna, Una |
| Lithuania | 6 | April | Celestinas, Daugirutis, Genardas, Zintaute |
| Poland | 6 | April | Ada, Adam, Adamina, Celestyn, Celestyna, Diogenes, Ireneusz, Katarzyna, Świętobor, Sykstus, Wilhelm, Zachariasz |
 USA | 6 | April | Celesta, Celeste, Celestina, Celestine, Tyra |
 Greece | 10 | April | Eteoklis, Hercules, Homer, Timothy, Dionisis, Pericles, Sofocles |
| France | 12 | April | Jules |
 Czechia | 13 | April | Aleš |
| Slovakia | 13 | April | Aleš |
| Spain | 22 | April | Teodoro, Alexander, Apeles |
| Greece | 24 | April | Elizabeth, Lisa, Anastasios, Doukas, Achilles, Orthodox Easter |
 Norway | 27 | April | Charles, Charlotte, Lotte |
| USA | 30 | April | Miles, Milo, Myles, Ryder |
| Slovakia | 5 | May | Lesana |
 Estonia | 7 | May | Helme, Helmi, Helma, Helmeles |
| USA | 12 | May | Achilla, Achilles, Grady, Grant, Kelby, Kellen |
 Croatia | 19 | May | Celestin V. p., Rajko, Teofil, Inka |
| France | 19 | May | Célestin, Erwan, Yves |
| Italy | 19 | May | Celestino V |
| Lithuania | 19 | May | Celestinas, Gilvinas, Taura |
| Poland | 19 | May | Augustyn, Celestyn, Iwo, Mikołaj, Pękosław, Piotr, Potencjana |
| Spain | 19 | May | Celestina, Celestino, Crispín |
 Ukraine | 25 | May | Celestine, Celeste |
| Poland | 3 | June | Cecyliusz, Ferdynand, Klotylda, Konstantyn, Laurencjusz, Laurentyn, Laurentyna, Leszek, Paula, Tamara, Wawrzyniec |
| Latvia | 9 | June | Gita, Liega, Ligita, Naula, Valeska |
| Italy | 27 | June | Cirillo di Alessandria |
| Italy | 17 | July | Alessio |
 Hungary | 20 | July | Illés |
| USA | 20 | July | Edna, Edwin, Edwina, Elias, Elijah, Ellice, Elliot, Elliott, Ellis, Ellison, Neal, Neala, Neil, Neila, Nelson, Niall, Nigel, Niles |
| Poland | 22 | July | Albin, Bolesława, Bolisława, Laurencjusz, Maria Magdalena, Milenia, Pankracy, Wawrzyniec, Więcemiła |
| Italy | 27 | July | Celestino I |
| Greece | 1 | August | Elesa |
| Spain | 2 | August | Angeles, Eusebio |
| Lithuania | 19 | August | Argaudas, Balys, Boleslovas, Tolvina |
| Poland | 19 | August | Bolesław, Emilia, Jan, Julian, Juliusz, Ludwik, Piotr, Sebald |
| Latvia | 24 | August | Bertolds, Bertrams, Berts, Bertulis, Boleslavs |
| Italy | 26 | August | Alessandro |
| France | 1 | September | Gilles, Jossué |
| USA | 1 | September | Debbie, Deborah, Debra, Edgar, Edgardo, Giles, Josh, Joshua, Josue, Ruth |
| Poland | 5 | September | Dorota, Herakles, Herkulan, Herkules, Justyna, Laurencjusz, Stronisława, Wawrzyniec |
| Czechia | 6 | September | Boleslav |
| Spain | 2 | October | Angeles Custodios |
| France | 14 | October | Céleste, Gwendoline, Juste |
| Hungary | 2 | November | Achilles |
| France | 4 | November | Aymeric, Charles, Jessé |
| USA | 4 | November | Amory, Cara, Carl, Carla, Carley, Carlo, Carlos, Carly, Carol, Carolina, Caroline, Carolyn, Carrie, Carroll, Charles, Charlie, Chaz, Chuck, Emery, Karl, Karla, Karlee, Karli, Karly |
| Poland | 7 | November | Achilles, Antoni, Engelbert, Florentyn, Melchior, Przemił |
| Italy | 25 | November | Caterina d'Alessandria |
| Poland | 28 | November | Gościrad, Grzegorz, Jakub, Lesław, Lesława, Rufin, Zdzisław |
 Austria | 1 | December | Blanka, Charles, Eligius, Natalie |