diff --git a/target/README.md b/target/README.md
index 06f239e..337565f 100644
--- a/target/README.md
+++ b/target/README.md
@@ -10,6 +10,26 @@ Java test target for [time-mocker](https://github.com/tiennm99/time-mocker) —
 
 Run alongside `time-mocker` to verify that system time injection works correctly.
 
+## Expected behavior
+
+**Without time-mocker** — prints actual current time, ticking every second:
+
+```
+2025-01-15T08:30:01
+2025-01-15T08:30:02
+2025-01-15T08:30:03
+```
+
+**With time-mocker injecting a fake date** (e.g. 2000-06-15T12:00:00) — the same binary prints the mocked time instead:
+
+```
+2000-06-15T12:00:01
+2000-06-15T12:00:02
+2000-06-15T12:00:03
+```
+
+If the output reflects the injected date rather than real system time, the injection is working correctly.
+
 ## License
 
 Apache-2.0 — see [LICENSE](LICENSE).