Tani's name day is December 11 in Estonia.
Tani is an uncommon name in the USA, used sporadically and often recognized as a diminutive, although its usage is consistent across decades. Its origins are diverse, stemming potentially from Slavic diminutives like Tanya or the Japanese word for "valley." Globally, Tani functions largely as a unisex name, fitting comfortably across genders depending on regional usage. The name projects a mood of playful elegance, characterized by its short, energetic sound and approachability. Historically, it reflects varied cultural adoption patterns rather than a single dominant lineage.
| Country | Day | Month | Names |
 USA | 5 | January | Ladarius, Ladd, Laird, Lamont, Lane, Tania, Tanya, Tatiana, Tatyana, Tawni, Tawnya, Tia, Tiana, Tianna, Tonya |
 Spain | 12 | January | Alfredo, Tatiana, Tania, Hilario |
 Ukraine | 12 | January | Tetiana, Tania |
| USA | 1 | February | Birgit, Birgitta, Bret, Brett, Bridget, Bridgette, Brigitte, Brita, Britney, Britt, Brittani, Brittany, Brittney, Brytanni, Clark, Clarke, Langdon, Langston |
 Lithuania | 1 | March | Albinas, Antanina, Rusne, Tulgaudas |
 Austria | 11 | April | Hildebrand, Stanislaus |
 Croatia | 11 | April | Stanislav, Stana, Radmila |
 France | 11 | April | Stanislas |
 Italy | 11 | April | Stanislao |
| Spain | 11 | April | Gema, Oria, Estanislao |
 Bulgaria | 12 | April | Vencislav, Vencislava, Violeta, Varban, Girgin, Girgina, Dilyan, Dilyana, Zdravka, Zdravko, Latinka, Lilyana, Margarita, Nevena, Roza, Rosen, Rosica, Trendafil, Trendafilka, Tsvetan, Tsveta, Tsvetanka, Tsviatko, Tseno, Stanislav, Stanislava |
 Czechia | 7 | May | Stanislav |
| Lithuania | 7 | May | Butautas, Danute, Rimte, Stanislovas, Stasys |
 Denmark | 8 | May | Stanislaus |
 Latvia | 8 | May | Aiga, Ceronis, Inita, Stanislavs, Stefanija |
 Poland | 8 | May | Dezyderia, Ilza, Marek, Michał, Piotr, Stanisław |
| 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 |
| Czechia | 9 | June | Stanislava |
 Slovakia | 9 | June | Stanislava |
| Poland | 5 | August | Cyriak, Emil, Karolin, Maria, Nonna, Oswald, Oswalda, Stanisława |
| Lithuania | 5 | September | Dingaile, Erdenis, Justina, Stanislova, Stase |
| Poland | 2 | October | Dionizy, Leodegar, Stanimir, Teofil, Trofim |
| Austria | 13 | November | Eugen, Livia, Stanislaus |
| Croatia | 13 | November | Stanislav Kostka, Brcko b., Stanko |
| Poland | 13 | November | Arkadiusz, Arkady, Brykcjusz, Eugeniusz, Jan, Mikołaj, Stanisław, Walentyn |
| Slovakia | 13 | November | Stanislav |
| Bulgaria | 5 | December | Elisaveta, Sava, Savka, Svetoslav, Svetoslava, Slavi, Slavcho, Sabi, Savina, Stanislav |
| Bulgaria | 27 | December | Venci, Vencislav, Vencislava, Zapryan, Sonya, Stamen, Stanimir, Stanka, Stefan, Stefana, Stefaniya, Stefka, Stoil, Stoimen, Stoichko, Stojko, Stoyan, Stoyanka, Tanya, Tsanka, Tsanko, Tsonka, Tsonyu |
Estonia