diff --git a/docs/journal-types.md b/docs/journal-types.md
index 8f5052153..3b3114560 100644
--- a/docs/journal-types.md
+++ b/docs/journal-types.md
@@ -22,9 +22,7 @@ use any extension. `jrnl` will automatically create the file when you save
 your first entry.
 
 ## Folder
-The folder journal format organizes your entries into subfolders for the year
-and month and `.txt` files for each day. If there are multiple entries in a day,
-they all appear in the same `.txt` file.
+The folder journal format organizes your entries into subfolders for the year and month, and a new file for each day. If there are multiple entries in a day, they all appear in the same file. The file extension (`.txt` by default) can be configured with the `extension` configuration key.
 
 The directory tree structure is in this format: `YYYY/MM/DD.txt`. For instance, if
 you have an entry on May 5th, 2021 in a folder journal at `~/folderjournal`, it will
diff --git a/docs/reference-config-file.md b/docs/reference-config-file.md
index aa64adb16..5aab5cd1f 100644
--- a/docs/reference-config-file.md
+++ b/docs/reference-config-file.md
@@ -57,6 +57,15 @@ for details.
 If `true`, encrypts your journal using AES. Do not change this
 value for journals that already have data in them.
 
+### extension
+
+For [folder journals](journal-types.md#folder), control the extension of the day
+files. By default it is `.txt`. 
+
+!!! warning
+    Changing the extension after a folder journal has been created will prevent 
+    `jrnl` from finding past entries.
+
 ### template
 The path to a text file to use as a template for new entries. Only works when you
 have the `editor` field configured. If you use a template, the editor's
diff --git a/jrnl/journals/FolderJournal.py b/jrnl/journals/FolderJournal.py
index c6faf1e02..00416e7db 100644
--- a/jrnl/journals/FolderJournal.py
+++ b/jrnl/journals/FolderJournal.py
@@ -17,7 +17,9 @@
 DIGIT_PATTERN = "[0123456789]"
 YEAR_PATTERN = DIGIT_PATTERN * 4
 MONTH_PATTERN = "[01]" + DIGIT_PATTERN
-DAY_PATTERN = "[0123]" + DIGIT_PATTERN + ".txt"
+DAY_PATTERN = "[0-3][0-9]"
+
+DEFAULT_EXTENSION = ".txt"
 
 
 class Folder(Journal):
@@ -34,7 +36,8 @@ def open(self) -> "Folder":
         self.entries = []
 
         if os.path.exists(self.config["journal"]):
-            filenames = Folder._get_files(self.config["journal"])
+            file_extension = self.config.get("extension", DEFAULT_EXTENSION)
+            filenames = Folder._get_files(self, self.config["journal"], file_extension)
             for filename in filenames:
                 with codecs.open(filename, "r", "utf-8") as f:
                     journal = f.read()
@@ -45,6 +48,8 @@ def open(self) -> "Folder":
 
     def write(self) -> None:
         """Writes only the entries that have been modified into proper files."""
+        file_extension = self.config.get("extension", DEFAULT_EXTENSION)
+
         # Create a list of dates of modified entries. Start with diff_entry_dates
         modified_dates = self._diff_entry_dates
         seen_dates = set(self._diff_entry_dates)
@@ -63,7 +68,7 @@ def write(self) -> None:
                 self.config["journal"],
                 d.strftime("%Y"),
                 d.strftime("%m"),
-                d.strftime("%d") + ".txt",
+                d.strftime("%d") + file_extension,
             )
             dirname = os.path.dirname(filename)
             # create directory if it doesn't exist
@@ -81,7 +86,7 @@ def write(self) -> None:
                 journal_file.write(journal)
         # look for and delete empty files
         filenames = []
-        filenames = Folder._get_files(self.config["journal"])
+        filenames = Folder._get_files(self, self.config["journal"], file_extension)
         for filename in filenames:
             if os.stat(filename).st_size <= 0:
                 os.remove(filename)
@@ -121,12 +126,12 @@ def parse_editable_str(self, edited: str) -> None:
         self.entries = mod_entries
 
     @staticmethod
-    def _get_files(journal_path: str) -> list[str]:
+    def _get_files(self, journal_path: str, extension: str) -> list[str]:
         """Searches through sub directories starting with journal_path and find all text
         files that look like entries"""
         for year_folder in Folder._get_year_folders(pathlib.Path(journal_path)):
             for month_folder in Folder._get_month_folders(year_folder):
-                yield from Folder._get_day_files(month_folder)
+                yield from Folder._get_day_files(month_folder, extension)
 
     @staticmethod
     def _get_year_folders(path: pathlib.Path) -> list[pathlib.Path]:
@@ -143,15 +148,16 @@ def _get_month_folders(path: pathlib.Path) -> list[pathlib.Path]:
         return
 
     @staticmethod
-    def _get_day_files(path: pathlib.Path) -> list[str]:
-        for child in path.glob(DAY_PATTERN):
+    def _get_day_files(path: pathlib.Path, extension: str) -> list[str]:
+        for child in path.glob(DAY_PATTERN + extension):
+            day = str(child.name).replace(extension, "")
             if (
-                int(child.stem) > 0
-                and int(child.stem) <= 31
+                int(day) > 0
+                and int(day) <= 31
                 and time.is_valid_date(
                     year=int(path.parent.name),
                     month=int(path.name),
-                    day=int(child.stem),
+                    day=int(day),
                 )
                 and child.is_file()
             ):
diff --git a/tests/bdd/features/file_storage.feature b/tests/bdd/features/file_storage.feature
index cecb21f65..9928558a1 100644
--- a/tests/bdd/features/file_storage.feature
+++ b/tests/bdd/features/file_storage.feature
@@ -10,13 +10,22 @@ Feature: Journals iteracting with the file system in a way that users can see
         And the journal directory should contain
             2013/07/23.txt
 
+    @skip_win # https://github.com/jrnl-org/jrnl/issues/1894
+    Scenario: Adding entries to a Folder journal with a custom extension should generate date files
+        Given we use the config "empty_folder_with_extension.yaml"
+        When we run "jrnl 23 July 2013: Testing folder journal."
+        Then we should get no error
+        And the journal directory should contain
+            2013/07/23.md
+
     Scenario: Adding multiple entries to a Folder journal should generate multiple date files
         Given we use the config "empty_folder.yaml"
         When we run "jrnl 23 July 2013: Testing folder journal."
-        And we run "jrnl 3/7/2014: Second entry of journal."
+        And we run "jrnl 5/3/2014: Second entry of journal."
         Then we should get no error
         And the journal directory should contain
             2013/07/23.txt
+            2014/05/03.txt
 
     Scenario: If the journal and its parent directory don't exist, they should be created
         Given we use the config "missing_directory.yaml"
diff --git a/tests/data/configs/empty_folder_with_extension.yaml b/tests/data/configs/empty_folder_with_extension.yaml
new file mode 100644
index 000000000..2ba99ef3c
--- /dev/null
+++ b/tests/data/configs/empty_folder_with_extension.yaml
@@ -0,0 +1,13 @@
+default_hour: 9
+default_minute: 0
+editor: ''
+template: false
+encrypt: false
+extension: .md
+highlight: true
+journals:
+  default: features/journals/empty_folder_with_extension/
+linewrap: 80
+tagsymbols: '@'
+timeformat: '%Y-%m-%d %H:%M'
+indent_character: "|"
diff --git a/tests/unit/test_journals_folder_journal.py b/tests/unit/test_journals_folder_journal.py
index 09a3535f8..e6785df78 100644
--- a/tests/unit/test_journals_folder_journal.py
+++ b/tests/unit/test_journals_folder_journal.py
@@ -51,7 +51,7 @@ def test_get_day_files_expected_filtering(inputs_and_outputs):
         mock.patch("pathlib.Path.glob", return_value=glob_files),
         mock.patch.object(pathlib.Path, "is_file", return_value=True),
     ):
-        actual_output = list(Folder._get_day_files(year_month_path))
+        actual_output = list(Folder._get_day_files(year_month_path, ".txt"))
         actual_output.sort()
 
         expected_output.sort()