diff --git a/erpnext/projects/doctype/timesheet_detail/timesheet_detail.py b/erpnext/projects/doctype/timesheet_detail/timesheet_detail.py
index 5f367428644..3dbb8614fa4 100644
--- a/erpnext/projects/doctype/timesheet_detail/timesheet_detail.py
+++ b/erpnext/projects/doctype/timesheet_detail/timesheet_detail.py
@@ -5,7 +5,7 @@
 import frappe
 from frappe import _
 from frappe.model.document import Document
-from frappe.utils import add_to_date, flt, get_datetime, time_diff_in_hours
+from frappe.utils import add_to_date, flt, get_datetime, time_diff_in_hours, time_diff_in_seconds
 
 
 class TimesheetDetail(Document):
@@ -48,7 +48,9 @@ class TimesheetDetail(Document):
 		if not (self.from_time and self.hours):
 			return
 
-		self.to_time = get_datetime(add_to_date(self.from_time, hours=self.hours, as_datetime=True))
+		_to_time = get_datetime(add_to_date(self.from_time, hours=self.hours, as_datetime=True))
+		if abs(time_diff_in_seconds(_to_time, self.to_time)) >= 1:
+			self.to_time = _to_time
 
 	def set_project(self):
 		"""Set project based on task."""