diff --git a/README.md b/README.md
index c43c6d7..4e53a3e 100644
--- a/README.md
+++ b/README.md
@@ -49,9 +49,9 @@ i. e. the text between the end of the "!echo" and the end of the whole message.
 
 ## TODOs
 
-- [ ] implement !uptime for proper botrulez conformity
 - [ ] implement !kill
 - [ ] implement !restart and add an easier way to run bots
+- [ ] untruncate LiveMessage-s
 - [ ] config file support for bots, used by default
 - [ ] package in a distutils-compatible way (users should be able to install
   yaboli using `pip install git+https://github.com/Garmelon/yaboli`)
@@ -62,3 +62,4 @@ i. e. the text between the end of the "!echo" and the end of the whole message.
 - [ ] document new classes (docstrings, maybe comments)
 - [ ] write project readme
 - [ ] write examples
+- [x] implement !uptime for proper botrulez conformity
diff --git a/yaboli/bot.py b/yaboli/bot.py
index 942470d..cc6a74a 100644
--- a/yaboli/bot.py
+++ b/yaboli/bot.py
@@ -1,3 +1,4 @@
+import datetime
 import logging
 from typing import List, Optional
 
@@ -5,6 +6,7 @@ from .client import Client
 from .command import *
 from .message import LiveMessage, Message
 from .room import Room
+from .util import *
 
 logger = logging.getLogger(__name__)
 
@@ -20,6 +22,8 @@ class Bot(Client):
 
         self._commands: List[Command] = []
 
+        self.start_time = datetime.datetime.now()
+
     # Registering commands
 
     def register(self, command: Command) -> None:
@@ -74,7 +78,8 @@ class Bot(Client):
 
     def register_botrulez(self,
             ping: bool = True,
-            help_: bool = True
+            help_: bool = True,
+            uptime: bool = True
             ) -> None:
         if ping:
             self.register_general("ping", self.cmd_ping, args=False)
@@ -87,6 +92,9 @@ class Bot(Client):
             self.register_general("help", self.cmd_help_general, args=False)
             self.register_specific("help", self.cmd_help_specific, args=False)
 
+        if uptime:
+            self.register_specific("uptime", self.cmd_uptime, args=False)
+
     async def cmd_ping(self,
             room: Room,
             message: LiveMessage,
@@ -109,3 +117,13 @@ class Bot(Client):
             ) -> None:
         if self.HELP_SPECIFIC is not None:
             await message.reply(self.format_help(room, self.HELP_SPECIFIC))
+
+    async def cmd_uptime(self,
+            room: Room,
+            message: LiveMessage,
+            args: SpecificArgumentData
+            ) -> None:
+        time = format_time(self.start_time)
+        delta = format_delta(datetime.datetime.now() - self.start_time)
+        text = f"/me has been up since {time} UTC ({delta})"
+        await message.reply(text)
diff --git a/yaboli/util.py b/yaboli/util.py
index 5353ec1..6439799 100644
--- a/yaboli/util.py
+++ b/yaboli/util.py
@@ -1,6 +1,8 @@
+import datetime
 import re
 
-__all__ = ["mention", "atmention", "normalize", "similar", "plural"]
+__all__ = ["mention", "atmention", "normalize", "similar", "plural",
+        "format_time", "format_delta"]
 
 # Name/nick related functions
 
@@ -28,3 +30,36 @@ def plural(
         return if_singular
     else:
         return if_plural
+
+def format_time(time: datetime.datetime) -> str:
+    return time.strftime("%F %T")
+
+def format_delta(delta: datetime.timedelta) -> str:
+    seconds = int(delta.total_seconds())
+    negative = seconds < 0
+    seconds = abs(seconds)
+
+    days = seconds // (60 * 60 * 24)
+    seconds -= days * (60 * 60 * 24)
+
+    hours = seconds // (60 * 60)
+    seconds -= hours * (60 * 60)
+
+    minutes = seconds // 60
+    seconds -= minutes * 60
+
+    text: str
+
+    if days > 0:
+        text = f"{days}d {hours}h {minutes}m {seconds}s"
+    elif hours > 0:
+        text = f"{hours}h {minutes}m {seconds}s"
+    elif minutes > 0:
+        text = f"{minutes}m {seconds}s"
+    else:
+        text = f"{seconds}s"
+
+    if negative:
+        text = "- " + text
+
+    return text