diff --git a/erpnext/projects/doctype/timesheet/timesheet.py b/erpnext/projects/doctype/timesheet/timesheet.py
index 19b9a45a7d2..9e7d00329dc 100644
--- a/erpnext/projects/doctype/timesheet/timesheet.py
+++ b/erpnext/projects/doctype/timesheet/timesheet.py
@@ -191,6 +191,9 @@ class Timesheet(Document):
 			}, as_dict=True)
 		# check internal overlap
 		for time_log in self.time_logs:
+			if not (time_log.from_time and time_log.to_time
+				and args.from_time and args.to_time): continue
+
 			if (fieldname != 'workstation' or args.get(fieldname) == time_log.get(fieldname)) and \
 				args.idx != time_log.idx and ((args.from_time > time_log.from_time and args.from_time < time_log.to_time) or
 				(args.to_time > time_log.from_time and args.to_time < time_log.to_time) or