diff --git a/src/tardyclock/cli.py b/src/tardyclock/cli.py
index 0da1fa6..d90dff0 100644
--- a/src/tardyclock/cli.py
+++ b/src/tardyclock/cli.py
@@ -1,12 +1,28 @@
 import typer
 from .core import random_time
 
+DEFAULT_TIME_FORMAT = "%A %B %m, %Y, %H:%M:%S"
+DEFAULT_TIME_FORMAT_12_HOUR = "%A %B %m, %Y, %I:%M:%S"
+
 tardy = typer.Typer()
 
 
 @tardy.command()
-def tell(hr24: bool = True, showtimezone: bool = False):
-  print(random_time(hr24=hr24, showtimezone=showtimezone))
+def tell(
+  hr24: bool = True,
+  showtimezone: bool = False,
+  time_format: str = DEFAULT_TIME_FORMAT,
+):
+  if not hr24 and time_format == DEFAULT_TIME_FORMAT:
+    time_format = DEFAULT_TIME_FORMAT_12_HOUR
+
+  print(
+    random_time(
+      hr24=hr24,
+      showtimezone=showtimezone,
+      time_format=time_format,
+    )
+  )
 
 
 if __name__ == "__main__":
diff --git a/src/tardyclock/core.py b/src/tardyclock/core.py
index 024a88e..a4b666b 100644
--- a/src/tardyclock/core.py
+++ b/src/tardyclock/core.py
@@ -3,13 +3,24 @@
 import pytz
 
 
-def random_time(hr24: bool = True, showtimezone: bool = False):
+def random_time(
+  hr24: bool = True,
+  showtimezone: bool = False,
+  time_format: str | None = None,
+):
   """Tells you the current time in a timezone of its choosing"""
   tz = pytz.timezone(choice(pytz.all_timezones))
   now = datetime.now(tz)
 
-  time_format = f"%A %B %m, %Y, {'%H' if hr24 else '%I'}:%M:%S"
-  if showtimezone:
+  if time_format is None:
+    time_format = f"%A %B %m, %Y, {'%H' if hr24 else '%I'}:%M:%S"
+  else:
+    if hr24 and "%I" in time_format and "%H" not in time_format:
+      time_format = time_format.replace("%I", "%H")
+    elif not hr24 and "%H" in time_format and "%I" not in time_format:
+      time_format = time_format.replace("%H", "%I")
+
+  if showtimezone and "%Z" not in time_format:
     time_format += " %Z"
 
   return now.strftime(time_format)