Fix to [Bug 499773] 
replace the ':' character with '_' in the time stamp used as part of
folder names by stem loggers. The ':' character is not allowed in folder
names on some window versions
diff --git a/core/org.eclipse.stem.jobs/src/org/eclipse/stem/jobs/execution/Executable.java b/core/org.eclipse.stem.jobs/src/org/eclipse/stem/jobs/execution/Executable.java
index baa122d..a82bf2e 100644
--- a/core/org.eclipse.stem.jobs/src/org/eclipse/stem/jobs/execution/Executable.java
+++ b/core/org.eclipse.stem.jobs/src/org/eclipse/stem/jobs/execution/Executable.java
@@ -94,7 +94,12 @@
 		sb.append("-");
 		sb.append(getSequenceNumber());
 		sb.append("-");
-		sb.append(DublinCoreImpl.createISO8601DateStringSeconds(getCreationTime()));
+		// the ':' character is not allowed in a folder name in some Windows versions so
+		// here it is replaced by '_'
+		String winSafestmp = DublinCoreImpl.createISO8601DateStringSeconds(getCreationTime());
+		sb.append(winSafestmp.replace(":", "_"));
+		
+		//sb.append(DublinCoreImpl.createISO8601DateStringSeconds(getCreationTime()));
 		// for milli-sec resolution use the following
 		// sb.append(DublinCoreImpl.createISO8601DateString(getCreationTime()));
 		return sb.toString();