added validate posting time method
diff --git a/utilities/transaction_base.py b/utilities/transaction_base.py
index 905e98f..2dc8c6a 100644
--- a/utilities/transaction_base.py
+++ b/utilities/transaction_base.py
@@ -16,7 +16,7 @@
 
 from __future__ import unicode_literals
 import webnotes
-from webnotes.utils import load_json, cstr, flt
+from webnotes.utils import load_json, cstr, flt, now_datetime
 from webnotes.model.doc import addchild
 
 from webnotes.model.controller import DocListController
@@ -246,4 +246,8 @@
 		[d.update({"doctype":"Communication"}) for d in comm_list]
 		
 		self.doclist.extend(webnotes.doclist([webnotes.doc(fielddata=d) \
-			for d in comm_list]))
\ No newline at end of file
+			for d in comm_list]))
+			
+	def validate_posting_time(self):
+		if not self.doc.posting_time:
+			self.doc.posting_time = now_datetime().strftime('%H:%M:%S')
\ No newline at end of file