diff --git a/app/src/plugins/tm@modal/task/_components/_components/a-task-timeblocks.vue b/app/src/plugins/tm@modal/task/_components/_components/a-task-timeblocks.vue
index f1df6e3..b30b96d 100644
--- a/app/src/plugins/tm@modal/task/_components/_components/a-task-timeblocks.vue
+++ b/app/src/plugins/tm@modal/task/_components/_components/a-task-timeblocks.vue
@@ -101,7 +101,6 @@ export default {
 				return
 
 			const subtask = JSON.parse(JSON.stringify(this.subtask))
-
 			const splittedStartsAtTime 	= this.form.starts_at_time.split(':')
 			const splittedEndsAtTime 	= this.form.ends_at_time.split(':')
 			const start = moment(this.form.date).hours(parseInt(splittedStartsAtTime[0])).minutes(parseInt(splittedStartsAtTime[1])).toISOString()
@@ -118,7 +117,7 @@ export default {
 				start: tmUtils.formatDateTimeForBackend(start)
 			})
 
-			subtask.deadline = tmUtils.formatDateTimeForBackend(subtask.deadline)
+			if(subtask.deadline) subtask.deadline = tmUtils.formatDateTimeForBackend(subtask.deadline)
 
 			if (!subtask.id) {
 				this.$emit('update-unfinished-subtask', subtask)
@@ -159,6 +158,7 @@ export default {
 		async deleteTimeblock({ id }) {
 			const subtask = JSON.parse(JSON.stringify(this.subtask))
 			subtask.timeblocks = subtask.timeblocks.filter(timeblock => timeblock.id != id)
+			if(subtask.deadline) subtask.deadline = tmUtils.formatDateTimeForBackend(subtask.deadline)
 
 			this._update(subtask)
 		},
@@ -173,6 +173,7 @@ export default {
 					delete timesheet.employee_name
 					return timesheet
 				})
+
 				const { subtask } = await this.$axios.put_auth(`v1/subtasks/${data.id}`, {...data, timesheets})
 
 				this.closeModal()