diff --git a/src/browser/utils.browser.ts b/src/browser/utils.browser.ts
index 2c62f133..88898302 100644
--- a/src/browser/utils.browser.ts
+++ b/src/browser/utils.browser.ts
@@ -4,6 +4,7 @@ import CH from '../locales/cmn-Hant/text.json';
 import CHS from '../locales/ch-CHS/text.json';
 import E from '../locales/en/text.json';
 import F from '../locales/fr-FR/text.json';
+import FI from '../locales/fi-FI/text.json';
 import I from '../locales/it-IT/text.json';
 import J from '../locales/ja-JP/text.json';
 import K from '../locales/uk-UA/text.json';
@@ -31,6 +32,6 @@ declare global {
 }
 
 window.jw_epub_parser = {
-  languages: { CH, CHS, E, F, I, J, K, KO, M, MG, P, S, T, TG, TK, TND, TNK, TPO, TTM, TW, U, VZ, X },
+  languages: { CH, CHS, E, F, FI, I, J, K, KO, M, MG, P, S, T, TG, TK, TND, TNK, TPO, TTM, TW, U, VZ, X },
   path: path,
 };
diff --git a/src/common/date_parser.ts b/src/common/date_parser.ts
index e0f743dd..1f13e5fd 100644
--- a/src/common/date_parser.ts
+++ b/src/common/date_parser.ts
@@ -69,6 +69,7 @@ const mwbDatePatterns: LangRegExp = {
   CH: new RegExp(mwbDatePatternJ, 'giu'),
   CHS: new RegExp(mwbDatePatternJ, 'giu'),
   E: new RegExp(mwbDatePatternE, 'giu'),
+  FI: new RegExp(mwbDatePatternX, 'giu'),
   J: new RegExp(mwbDatePatternJ, 'giu'),
   KO: new RegExp(mwbDatePatternKO, 'giu'),
   P: new RegExp(mwbDatePatternP, 'giu'),
@@ -230,11 +231,18 @@ option1 = `(\\d{1,2}). bis (?:\\d{1,2}).? (${wordWithDiacritics}) (\\d{4})`;
 option2 = `(\\d{1,2}). (${wordWithDiacritics}) (\\d{4})`;
 const wDatePatternX = `${option1}|${option2}`;
 
+// date like 1-) Tutkitaan 3.–9.2.2025 ; or 2) Tutkitaan 24.2.–2.3.2025. ; or 3) Tutkitaan 30.12.2024–5.1.2025.
+option1 = '(\\d{1,2}).[–](?:\\d{1,2}).(\\d{1,2}).(\\d{4})';
+option2 = '(\\d{1,2}).(\\d{1,2}).[–](?:\\d{1,2}).(?:\\d{1,2}).(\\d{4})';
+option3 = '(\\d{1,2}).(\\d{1,2}).(\\d{4})';
+const wDatePatternFI = `${option1}|${option2}|${option3}`;
+
 const wDatePatterns: LangRegExp = {
   common: new RegExp(wDatePatternCommon, 'giu'),
   CH: new RegExp(wDatePatternJ, 'giu'),
   CHS: new RegExp(wDatePatternJ, 'giu'),
   E: new RegExp(wDatePatternE, 'giu'),
+  FI: new RegExp(wDatePatternFI, 'giu'),
   J: new RegExp(wDatePatternJ, 'giu'),
   KO: new RegExp(wDatePatternKO, 'giu'),
   P: new RegExp(wDatePatternP, 'giu'),
diff --git a/src/locales/languages.ts b/src/locales/languages.ts
index f54592d1..cf8423f4 100644
--- a/src/locales/languages.ts
+++ b/src/locales/languages.ts
@@ -1,25 +1,27 @@
 export default [
-	{ locale: 'en', code: 'E' },
-	{ locale: 'fr-FR', code: 'F' },
-	{ locale: 'it-IT', code: 'I' },
-	{ locale: 'ja-JP', code: 'J' },
-	{ locale: 'uk-UA', code: 'K' },
-	{ locale: 'ko-KR', code: 'KO' },
-	{ locale: 'ro-RO', code: 'M' },
-	{ locale: 'mg-MG', code: 'MG' },
-	{ locale: 'pl-PL', code: 'P' },
-	{ locale: 'es-ES', code: 'S' },
-	{ locale: 'pt-BR', code: 'T' },
-	{ locale: 'pt-PT', code: 'TPO'},
-	{ locale: 'tl-PH', code: 'TG' },
-	{ locale: 'tr-TR', code: 'TK' },
-	{ locale: 'mg-TND', code: 'TND' },
-	{ locale: 'mg-TNK', code: 'TNK' },
-	{ locale: 'mg-TTM', code: 'TTM' },
-	{ locale: 'tw-TW', code: 'TW' },
-	{ locale: 'uk-UA', code: 'U' },
-	{ locale: 'mg-VZ', code: 'VZ' },
-	{ locale: 'de-DE', code: 'X' },
-	{ locale: 'cmn-Hant', code: 'CH' },
-	{ locale: 'ch-CHS', code: 'CHS' },
+  { locale: 'en', code: 'E' },
+  { locale: 'fr-FR', code: 'F' },
+  { locale: 'it-IT', code: 'I' },
+  { locale: 'ja-JP', code: 'J' },
+  { locale: 'uk-UA', code: 'K' },
+  { locale: 'ko-KR', code: 'KO' },
+  { locale: 'ro-RO', code: 'M' },
+  { locale: 'mg-MG', code: 'MG' },
+  { locale: 'pl-PL', code: 'P' },
+  { locale: 'es-ES', code: 'S' },
+  { locale: 'pt-BR', code: 'T' },
+  { locale: 'pt-PT', code: 'TPO' },
+  { locale: 'tl-PH', code: 'TG' },
+  { locale: 'tr-TR', code: 'TK' },
+  { locale: 'mg-TND', code: 'TND' },
+  { locale: 'mg-TNK', code: 'TNK' },
+  { locale: 'mg-TTM', code: 'TTM' },
+  { locale: 'tw-TW', code: 'TW' },
+  { locale: 'uk-UA', code: 'U' },
+  { locale: 'mg-VZ', code: 'VZ' },
+  { locale: 'de-DE', code: 'X' },
+  { locale: 'cmn-Hant', code: 'CH' },
+  { locale: 'ch-CHS', code: 'CHS' },
+  { locale: 'fi-FI', code: 'FI' },
+  { locale: 'sv-SE', code: 'Z' },
 ];
diff --git a/src/node/utils.node.ts b/src/node/utils.node.ts
index 0cdbbce7..07d905c4 100644
--- a/src/node/utils.node.ts
+++ b/src/node/utils.node.ts
@@ -5,6 +5,7 @@ import CH from '../locales/cmn-Hant/text.json' assert { type: 'json' };
 import CHS from '../locales/ch-CHS/text.json' assert { type: 'json' };
 import E from '../locales/en/text.json' assert { type: 'json' };
 import F from '../locales/fr-FR/text.json' assert { type: 'json' };
+import FI from '../locales/fi-FI/text.json' assert { type: 'json' };
 import I from '../locales/it-IT/text.json' assert { type: 'json' };
 import J from '../locales/ja-JP/text.json' assert { type: 'json' };
 import K from '../locales/uk-UA/text.json' assert { type: 'json' };
@@ -30,7 +31,7 @@ declare global {
 }
 
 global.jw_epub_parser = {
-  languages: { CH, CHS, E, F, I, J, K, KO, M, MG, P, S, T, TG, TK, TND, TNK, TPO, TTM, TW, U, VZ, X },
+  languages: { CH, CHS, E, F, FI, I, J, K, KO, M, MG, P, S, T, TG, TK, TND, TNK, TPO, TTM, TW, U, VZ, X },
   path: path,
   readFile: readFile,
 };