Fixed local-timezone-brittle test where short-timezone form "EST" is ambiguous. Use -0500 instead. Fixed SPARK-15723.

Author: javabrett

core/src/test/scala/org/apache/spark/status/api/v1/SimpleDateParamSuite.scala

@@ -26,7 +26,7 @@ class SimpleDateParamSuite extends SparkFunSuite with Matchers {
 
   test("date parsing") {
     new SimpleDateParam("2015-02-20T23:21:17.190GMT").timestamp should be (1424474477190L)
-    new SimpleDateParam("2015-02-20T17:21:17.190EST").timestamp should be (1424470877190L)
+    new SimpleDateParam("2015-02-20T17:21:17.190-0500").timestamp should be (1424470877190L) // don't use EST, it is ambiguous, see SPARK-15723
     new SimpleDateParam("2015-02-20").timestamp should be (1424390400000L) // GMT
     intercept[WebApplicationException] {
       new SimpleDateParam("invalid date")