diff --git a/tests/git_filter_test.rs b/tests/git_filter_test.rs
new file mode 100644
index 0000000..99a5791
--- /dev/null
+++ b/tests/git_filter_test.rs
@@ -0,0 +1,40 @@
+#[cfg(test)]
+mod tests {
+    use crate::git::filter::{parse_date, TimeFilter, TimePeriod};
+    use crate::git::Repository;
+
+    #[test]
+    fn test_time_period_parsing() {
+        let period: TimePeriod = "7d".parse().unwrap();
+        let (start, end) = period.to_range();
+        assert!(end > start);
+    }
+
+    #[test]
+    fn test_time_period_weeks() {
+        let period: TimePeriod = "2w".parse().unwrap();
+        let (start, end) = period.to_range();
+        let days = (end - start).num_days();
+        assert!(days >= 14);
+    }
+
+    #[test]
+    fn test_time_period_months() {
+        let period: TimePeriod = "1m".parse().unwrap();
+        let (start, end) = period.to_range();
+        let days = (end - start).num_days();
+        assert!(days >= 28 && days <= 31);
+    }
+
+    #[test]
+    fn test_parse_date_relative() {
+        let date = parse_date("7d").unwrap();
+        assert!(date.year() > 2020);
+    }
+
+    #[test]
+    fn test_parse_date_iso() {
+        let date = parse_date("2024-01-15").unwrap();
+        assert!(date.year() == 2024);
+    }
+}