Add a test for #5430

testsuite/tests/lib/Time/T5430.hs

+
+import System.Locale
+import System.Time
+
+main :: IO ()
+main = do let clockTime = TOD 0 0 -- 00:00:00 on 1 Jan 1970
+          calTime <- toCalendarTime clockTime
+          putStrLn $ formatCalendarTime defaultTimeLocale "%j" calTime

testsuite/tests/lib/Time/T5430.stdout

+001

testsuite/tests/lib/Time/all.T

 test('time002', normal, compile_and_run, [''])
 test('time003', normal, compile_and_run, [''])
 test('time004', normal, compile_and_run, [''])
+test('T5430', normal, compile_and_run, [''])