phase: 20.49 COMPLETE; 20.50 Flow+String minimal reps; 20.51 selfhost v0/v1 minimal (Option A/B); hv1-inline binop/unop/copy; docs + run_all + CURRENT_TASK -> 21.0

tests/phase1/test_datetime_box.hako

@@ -0,0 +1,43 @@
+// test_datetime_box.hako - DateTimeBox functionality test
+// Phase 3: DateTimeBox implementation validation
+
+print("📅 Testing DateTimeBox implementation...")
+
+// Basic DateTimeBox creation
+local now, timestamp_dt, parsed_dt, result
+
+// Test 1: Current time creation
+now = new DateTimeBox()
+print("Current time: " + now.toString())
+
+// Test 2: Timestamp creation  
+timestamp_dt = new DateTimeBox(1640995200)  // 2022-01-01 00:00:00 UTC
+print("From timestamp: " + timestamp_dt.toString())
+
+// Test 3: Date component extraction
+result = now.year()
+print("Current year: " + result.toString())
+
+result = now.month()
+print("Current month: " + result.toString())
+
+result = now.day()
+print("Current day: " + result.toString())
+
+result = now.hour()
+print("Current hour: " + result.toString())
+
+result = now.minute()
+print("Current minute: " + result.toString())
+
+result = now.second()
+print("Current second: " + result.toString())
+
+// Test 4: Date arithmetic
+result = now.addDays(7)
+print("7 days from now: " + result.toString())
+
+result = now.addHours(24)
+print("24 hours from now: " + result.toString())
+
+print("✅ DateTimeBox Phase 3 tests completed!")