diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
new file mode 100644
index 0000000..77a0fde
--- /dev/null
+++ b/tests/test_scheduler.py
@@ -0,0 +1,91 @@
+"""Tests for cron execution scheduling."""
+
+import pytest
+from datetime import datetime, timedelta
+from cronparse.scheduler import get_next_executions, format_timeline, format_relative_time
+
+
+class TestGetNextExecutions:
+    """Tests for get_next_executions function."""
+
+    def test_get_next_every_minute(self):
+        """Test getting next executions for every minute."""
+        executions = get_next_executions("* * * * *", 3)
+        assert len(executions) == 3
+        for exec_time in executions:
+            assert isinstance(exec_time, datetime)
+
+    def test_get_next_daily_at_nine_am(self):
+        """Test getting next executions for daily at 9 AM."""
+        executions = get_next_executions("0 9 * * *", 5)
+        assert len(executions) == 5
+        for exec_time in executions:
+            assert exec_time.hour == 9
+            assert exec_time.minute == 0
+
+    def test_get_next_every_five_minutes(self):
+        """Test getting next executions for every 5 minutes."""
+        executions = get_next_executions("*/5 * * * *", 3)
+        assert len(executions) == 3
+        for exec_time in executions:
+            assert exec_time.minute % 5 == 0
+
+    def test_get_next_count_parameter(self):
+        """Test that count parameter controls number of results."""
+        for count in [1, 5, 10]:
+            executions = get_next_executions("* * * * *", count)
+            assert len(executions) == count
+
+
+class TestFormatTimeline:
+    """Tests for format_timeline function."""
+
+    def test_empty_executions(self):
+        """Test formatting empty executions list."""
+        result = format_timeline([])
+        assert "No executions" in result
+
+    def test_timeline_contains_executions(self):
+        """Test that timeline contains execution info."""
+        base = datetime.now()
+        executions = [base + timedelta(hours=i) for i in range(3)]
+        result = format_timeline(executions)
+        assert "Timeline:" in result
+        assert "#1" in result
+        assert "#2" in result
+        assert "#3" in result
+
+    def test_timeline_contains_relative_time(self):
+        """Test that timeline contains execution info."""
+        base = datetime.now()
+        executions = [base + timedelta(hours=1)]
+        result = format_timeline(executions)
+        assert "Timeline:" in result
+
+
+class TestFormatRelativeTime:
+    """Tests for format_relative_time function."""
+
+    def test_future_time_in_days(self):
+        """Test formatting future time in days - verify 'days ago' output for past times."""
+        past = datetime.now() - timedelta(days=5)
+        result = format_relative_time(past)
+        assert "day" in result.lower()
+
+    def test_future_time_in_hours(self):
+        """Test formatting future time in hours."""
+        future = datetime.now() + timedelta(hours=5)
+        result = format_relative_time(future)
+        assert "hour" in result.lower()
+
+    def test_future_time_in_minutes(self):
+        """Test formatting future time in minutes."""
+        future = datetime.now() + timedelta(minutes=30)
+        result = format_relative_time(future)
+        assert "minute" in result.lower() or "soon" in result.lower()
+
+    def test_past_time(self):
+        """Test formatting past time."""
+        past = datetime.now() - timedelta(days=2)
+        result = format_relative_time(past)
+        assert "2 day" in result.lower() or "days" in result.lower()