diff --git a/plugins/remind.py b/plugins/remind.py
index 7178fb5..87bbf7f 100644
--- a/plugins/remind.py
+++ b/plugins/remind.py
@@ -156,7 +156,9 @@ async def cmd_remind(bot, message):
         rest = parts[2] if len(parts) > 2 else ""
         parts = ["", "", *rest.split(None, 1)]  # re-split: [_, _, duration, text]
 
-    duration = _parse_duration(parts[1] if not repeating else parts[2])
+    dur_idx = 2 if repeating else 1
+    dur_spec = parts[dur_idx] if dur_idx < len(parts) else ""
+    duration = _parse_duration(dur_spec)
     if duration is None:
         await bot.reply(message, "Invalid duration (use: 5m, 1h30m, 2d, 90s)")
         return
diff --git a/tests/test_remind.py b/tests/test_remind.py
index 0836882..82f5df7 100644
--- a/tests/test_remind.py
+++ b/tests/test_remind.py
@@ -1,9 +1,12 @@
 """Tests for the remind plugin."""
 
+import asyncio
 import importlib.util
 import sys
 from pathlib import Path
 
+from derp.irc import Message
+
 # plugins/ is not a Python package -- load the module from file path
 _spec = importlib.util.spec_from_file_location(
     "plugins.remind", Path(__file__).resolve().parent.parent / "plugins" / "remind.py",
@@ -13,11 +16,81 @@ sys.modules[_spec.name] = _mod
 _spec.loader.exec_module(_mod)
 
 from plugins.remind import (  # noqa: E402
+    _by_user,
+    _cleanup,
     _format_duration,
     _make_id,
     _parse_duration,
+    _remind_once,
+    _remind_repeat,
+    _reminders,
+    cmd_remind,
 )
 
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+class _FakeBot:
+    """Minimal bot stand-in that captures sent/replied messages."""
+
+    def __init__(self):
+        self.sent: list[tuple[str, str]] = []
+        self.replied: list[str] = []
+
+    async def send(self, target: str, text: str) -> None:
+        self.sent.append((target, text))
+
+    async def reply(self, message, text: str) -> None:
+        self.replied.append(text)
+
+
+def _msg(text: str, nick: str = "alice", target: str = "#test") -> Message:
+    """Create a channel PRIVMSG."""
+    return Message(
+        raw="", prefix=f"{nick}!~{nick}@host", nick=nick,
+        command="PRIVMSG", params=[target, text], tags={},
+    )
+
+
+def _pm(text: str, nick: str = "alice") -> Message:
+    """Create a private PRIVMSG (target = bot nick)."""
+    return Message(
+        raw="", prefix=f"{nick}!~{nick}@host", nick=nick,
+        command="PRIVMSG", params=["botname", text], tags={},
+    )
+
+
+def _clear() -> None:
+    """Reset global module state between tests."""
+    for entry in _reminders.values():
+        task = entry[0]
+        if task is not None and not task.done():
+            task.cancel()
+    _reminders.clear()
+    _by_user.clear()
+
+
+async def _run_cmd(bot, msg):
+    """Run cmd_remind and cancel any spawned tasks afterward."""
+    await cmd_remind(bot, msg)
+    # Yield so tasks can start
+    await asyncio.sleep(0)
+
+
+async def _run_cmd_and_cleanup(bot, msg):
+    """Run cmd_remind, yield, then cancel all spawned tasks."""
+    await cmd_remind(bot, msg)
+    await asyncio.sleep(0)
+    for entry in list(_reminders.values()):
+        if entry[0] is not None and not entry[0].done():
+            entry[0].cancel()
+    await asyncio.sleep(0)
+
+
+# ---------------------------------------------------------------------------
+# Pure helpers: _parse_duration
+# ---------------------------------------------------------------------------
 
 class TestParseDurationRawSeconds:
     def test_positive_integer(self):
@@ -72,6 +145,10 @@ class TestParseDurationEdgeCases:
         assert _parse_duration("0d0h0m1s") == 1
 
 
+# ---------------------------------------------------------------------------
+# Pure helpers: _format_duration
+# ---------------------------------------------------------------------------
+
 class TestFormatDuration:
     def test_minutes_and_seconds(self):
         assert _format_duration(90) == "1m30s"
@@ -92,6 +169,10 @@ class TestFormatDuration:
         assert _format_duration(45) == "45s"
 
 
+# ---------------------------------------------------------------------------
+# Pure helpers: _make_id
+# ---------------------------------------------------------------------------
+
 class TestMakeId:
     def test_returns_six_char_hex(self):
         rid = _make_id("user", "check oven")
@@ -102,3 +183,421 @@ class TestMakeId:
         rid1 = _make_id("alice", "task one")
         rid2 = _make_id("bob", "task two")
         assert rid1 != rid2
+
+
+# ---------------------------------------------------------------------------
+# _cleanup
+# ---------------------------------------------------------------------------
+
+class TestCleanup:
+    def test_removes_from_both_structures(self):
+        _clear()
+        _reminders["abc123"] = (None, "#ch", "alice", "label", "12:00", False)
+        _by_user[("#ch", "alice")] = ["abc123"]
+
+        _cleanup("abc123", "#ch", "alice")
+
+        assert "abc123" not in _reminders
+        assert ("#ch", "alice") not in _by_user
+
+    def test_removes_single_entry_from_multi(self):
+        _clear()
+        _reminders["aaa"] = (None, "#ch", "alice", "", "12:00", False)
+        _reminders["bbb"] = (None, "#ch", "alice", "", "12:00", False)
+        _by_user[("#ch", "alice")] = ["aaa", "bbb"]
+
+        _cleanup("aaa", "#ch", "alice")
+
+        assert "aaa" not in _reminders
+        assert _by_user[("#ch", "alice")] == ["bbb"]
+
+    def test_missing_rid_no_error(self):
+        _clear()
+        _cleanup("nonexistent", "#ch", "alice")
+
+    def test_missing_user_key_no_error(self):
+        _clear()
+        _reminders["abc"] = (None, "#ch", "alice", "", "12:00", False)
+
+        _cleanup("abc", "#ch", "bob")  # different nick, user key absent
+
+        assert "abc" not in _reminders
+
+
+# ---------------------------------------------------------------------------
+# _remind_once
+# ---------------------------------------------------------------------------
+
+class TestRemindOnce:
+    def test_fires_metadata_and_label(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            rid = "once01"
+            task = asyncio.create_task(
+                _remind_once(bot, rid, "#ch", "alice", "check oven", 0, "12:00:00 UTC"),
+            )
+            _reminders[rid] = (task, "#ch", "alice", "check oven", "12:00:00 UTC", False)
+            _by_user[("#ch", "alice")] = [rid]
+            await task
+
+        asyncio.run(inner())
+        assert len(bot.sent) == 2
+        assert "alice: reminder #once01" in bot.sent[0][1]
+        assert "12:00:00 UTC" in bot.sent[0][1]
+        assert bot.sent[1] == ("#ch", "check oven")
+        assert "once01" not in _reminders
+
+    def test_empty_label_sends_one_line(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            rid = "once02"
+            task = asyncio.create_task(
+                _remind_once(bot, rid, "#ch", "bob", "", 0, "12:00:00 UTC"),
+            )
+            _reminders[rid] = (task, "#ch", "bob", "", "12:00:00 UTC", False)
+            _by_user[("#ch", "bob")] = [rid]
+            await task
+
+        asyncio.run(inner())
+        assert len(bot.sent) == 1
+
+    def test_cancellation_cleans_up(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            rid = "once03"
+            task = asyncio.create_task(
+                _remind_once(bot, rid, "#ch", "alice", "text", 9999, "12:00:00 UTC"),
+            )
+            _reminders[rid] = (task, "#ch", "alice", "text", "12:00:00 UTC", False)
+            _by_user[("#ch", "alice")] = [rid]
+            await asyncio.sleep(0)
+            task.cancel()
+            await asyncio.gather(task, return_exceptions=True)
+
+        asyncio.run(inner())
+        assert len(bot.sent) == 0
+        assert "once03" not in _reminders
+
+
+# ---------------------------------------------------------------------------
+# _remind_repeat
+# ---------------------------------------------------------------------------
+
+class TestRemindRepeat:
+    def test_fires_at_least_once(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            rid = "rpt01"
+            task = asyncio.create_task(
+                _remind_repeat(bot, rid, "#ch", "alice", "hydrate", 0, "12:00:00 UTC"),
+            )
+            _reminders[rid] = (task, "#ch", "alice", "hydrate", "12:00:00 UTC", True)
+            _by_user[("#ch", "alice")] = [rid]
+            for _ in range(5):
+                await asyncio.sleep(0)
+            task.cancel()
+            await asyncio.gather(task, return_exceptions=True)
+
+        asyncio.run(inner())
+        assert len(bot.sent) >= 2  # at least one fire (metadata + label)
+        assert any("rpt01" in t for _, t in bot.sent)
+        assert "rpt01" not in _reminders
+
+    def test_cancellation_cleans_up(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            rid = "rpt02"
+            task = asyncio.create_task(
+                _remind_repeat(bot, rid, "#ch", "bob", "stretch", 9999, "12:00:00 UTC"),
+            )
+            _reminders[rid] = (task, "#ch", "bob", "stretch", "12:00:00 UTC", True)
+            _by_user[("#ch", "bob")] = [rid]
+            await asyncio.sleep(0)
+            task.cancel()
+            await asyncio.gather(task, return_exceptions=True)
+
+        asyncio.run(inner())
+        assert len(bot.sent) == 0
+        assert "rpt02" not in _reminders
+
+
+# ---------------------------------------------------------------------------
+# cmd_remind: usage / errors
+# ---------------------------------------------------------------------------
+
+class TestCmdRemindUsage:
+    def test_no_args_shows_usage(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind")))
+        assert "Usage:" in bot.replied[0]
+
+    def test_invalid_duration(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind xyz some text")))
+        assert "Invalid duration" in bot.replied[0]
+
+    def test_every_no_args(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind every")))
+        assert "Invalid duration" in bot.replied[0]
+
+    def test_every_invalid_duration(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind every abc")))
+        assert "Invalid duration" in bot.replied[0]
+
+
+# ---------------------------------------------------------------------------
+# cmd_remind: one-shot creation
+# ---------------------------------------------------------------------------
+
+class TestCmdRemindOneshot:
+    def test_creates_with_duration(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd_and_cleanup(bot, _msg("!remind 5m check the oven"))
+
+        asyncio.run(inner())
+        assert len(bot.replied) == 1
+        assert "set (5m)" in bot.replied[0]
+        assert "#" in bot.replied[0]
+
+    def test_no_label(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd_and_cleanup(bot, _msg("!remind 5m"))
+
+        asyncio.run(inner())
+        assert "set (5m)" in bot.replied[0]
+
+    def test_stores_in_tracking(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind 9999s task"))
+            assert len(_reminders) == 1
+            entry = next(iter(_reminders.values()))
+            assert entry[1] == "#test"  # target
+            assert entry[2] == "alice"  # nick
+            assert entry[3] == "task"   # label
+            assert entry[5] is False    # not repeating
+            assert ("#test", "alice") in _by_user
+            # cleanup
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+
+    def test_days_duration(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd_and_cleanup(bot, _msg("!remind 2d12h renew cert"))
+
+        asyncio.run(inner())
+        assert "set (2d12h)" in bot.replied[0]
+
+
+# ---------------------------------------------------------------------------
+# cmd_remind: repeating creation
+# ---------------------------------------------------------------------------
+
+class TestCmdRemindRepeat:
+    def test_creates_repeating(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd_and_cleanup(bot, _msg("!remind every 1h drink water"))
+
+        asyncio.run(inner())
+        assert len(bot.replied) == 1
+        assert "every 1h" in bot.replied[0]
+
+    def test_repeating_stores_flag(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind every 30m stretch"))
+            entry = next(iter(_reminders.values()))
+            assert entry[5] is True  # repeating flag
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+
+    def test_repeating_no_label(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd_and_cleanup(bot, _msg("!remind every 1h"))
+
+        asyncio.run(inner())
+        assert "every 1h" in bot.replied[0]
+
+
+# ---------------------------------------------------------------------------
+# cmd_remind: list
+# ---------------------------------------------------------------------------
+
+class TestCmdRemindList:
+    def test_empty_list(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind list")))
+        assert "No active reminders" in bot.replied[0]
+
+    def test_shows_active(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind 9999s task"))
+            bot.replied.clear()
+            await cmd_remind(bot, _msg("!remind list"))
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+        assert "Reminders:" in bot.replied[0]
+        assert "#" in bot.replied[0]
+
+    def test_shows_repeat_tag(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind every 9999s task"))
+            bot.replied.clear()
+            await cmd_remind(bot, _msg("!remind list"))
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+        assert "(repeat)" in bot.replied[0]
+
+
+# ---------------------------------------------------------------------------
+# cmd_remind: cancel
+# ---------------------------------------------------------------------------
+
+class TestCmdRemindCancel:
+    def _extract_rid(self, reply: str) -> str:
+        """Extract reminder ID from 'Reminder #abc123 set (...)' reply."""
+        return reply.split("#")[1].split(" ")[0]
+
+    def test_cancel_valid(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind 9999s task"))
+            rid = self._extract_rid(bot.replied[0])
+            bot.replied.clear()
+            await cmd_remind(bot, _msg(f"!remind cancel {rid}"))
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+        assert "Cancelled" in bot.replied[0]
+
+    def test_cancel_with_hash_prefix(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind 9999s task"))
+            rid = self._extract_rid(bot.replied[0])
+            bot.replied.clear()
+            await cmd_remind(bot, _msg(f"!remind cancel #{rid}"))
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+        assert "Cancelled" in bot.replied[0]
+
+    def test_cancel_wrong_user(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind 9999s secret"))
+            rid = self._extract_rid(bot.replied[0])
+            bot.replied.clear()
+            await cmd_remind(bot, _msg(f"!remind cancel {rid}", nick="eve"))
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+        assert "No active reminder" in bot.replied[0]
+
+    def test_cancel_nonexistent(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind cancel ffffff")))
+        assert "No active reminder" in bot.replied[0]
+
+    def test_cancel_no_id(self):
+        _clear()
+        bot = _FakeBot()
+        asyncio.run(cmd_remind(bot, _msg("!remind cancel")))
+        assert "Usage:" in bot.replied[0]
+
+
+# ---------------------------------------------------------------------------
+# cmd_remind: target routing
+# ---------------------------------------------------------------------------
+
+class TestCmdRemindTarget:
+    def test_channel_target(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _msg("!remind 9999s task", target="#ops"))
+            entry = next(iter(_reminders.values()))
+            assert entry[1] == "#ops"
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())
+
+    def test_pm_uses_nick(self):
+        _clear()
+        bot = _FakeBot()
+
+        async def inner():
+            await _run_cmd(bot, _pm("!remind 9999s task"))
+            entry = next(iter(_reminders.values()))
+            assert entry[1] == "alice"  # nick, not "botname"
+            for e in _reminders.values():
+                e[0].cancel()
+            await asyncio.sleep(0)
+
+        asyncio.run(inner())