diff --git a/src/modules/businesses/businesses.service.ts b/src/modules/businesses/businesses.service.ts
index e911530..7e195e7 100644
--- a/src/modules/businesses/businesses.service.ts
+++ b/src/modules/businesses/businesses.service.ts
@@ -11,7 +11,10 @@ import { deleteBusinessCascade } from '../../common/utils/business-cascade.util'
 import { resolveUniqueSlug, normalizeSlugInput } from '../../common/utils/slug.util';
 import { BusinessImagesService } from './business-images.service';
 import { BusinessCategoryEntity } from '../../entities/business-category.entity';
-import { parseHmToMinute } from '../../common/utils/booking-schedule.util';
+import {
+  normalizeHmTimeInput,
+  parseHmToMinute,
+} from '../../common/utils/booking-schedule.util';
 import { BusinessAvailabilitySlotEntity } from '../../entities/business-availability-slot.entity';
 import { BusinessEntity } from '../../entities/business.entity';
 import { UserEntity, UserRole } from '../../entities/user.entity';
@@ -176,8 +179,15 @@ export class BusinessesService {
 
     const entities: BusinessAvailabilitySlotEntity[] = [];
     for (const slot of dto.slots) {
-      const startMinute = parseHmToMinute(slot.startTime);
-      const endMinute = parseHmToMinute(slot.endTime);
+      const startTime = normalizeHmTimeInput(slot.startTime);
+      const endTime = normalizeHmTimeInput(slot.endTime);
+      if (!startTime || !endTime) {
+        throw new BadRequestException(
+          'ساعت باید به صورت HH:mm باشد (مثلاً 09:00)',
+        );
+      }
+      const startMinute = parseHmToMinute(startTime);
+      const endMinute = parseHmToMinute(endTime);
       if (endMinute <= startMinute) {
         throw new BadRequestException('endTime must be after startTime');
       }
diff --git a/src/modules/businesses/dto/set-availability.dto.ts b/src/modules/businesses/dto/set-availability.dto.ts
index 09871bb..742df00 100644
--- a/src/modules/businesses/dto/set-availability.dto.ts
+++ b/src/modules/businesses/dto/set-availability.dto.ts
@@ -1,16 +1,14 @@
 import { ApiProperty } from '@nestjs/swagger';
-import { Transform, Type } from 'class-transformer';
+import { Type } from 'class-transformer';
 import {
   ArrayMaxSize,
   IsArray,
   IsInt,
   IsString,
-  Matches,
   Max,
   Min,
   ValidateNested,
 } from 'class-validator';
-import { normalizeHmTimeInput } from '../../../common/utils/booking-schedule.util';
 
 export class AvailabilitySlotDto {
   @ApiProperty({ description: '0=شنبه … 6=جمعه', minimum: 0, maximum: 6 })
@@ -20,16 +18,12 @@ export class AvailabilitySlotDto {
   @Max(6)
   dayOfWeek!: number;
 
-  @ApiProperty({ example: '09:00' })
-  @Transform(({ value }) => normalizeHmTimeInput(value) ?? value)
+  @ApiProperty({ example: '09:00', description: 'HH:mm 24h (9:00 also accepted)' })
   @IsString()
-  @Matches(/^([01]\d|2[0-3]):[0-5]\d]$/)
   startTime!: string;
 
-  @ApiProperty({ example: '17:00' })
-  @Transform(({ value }) => normalizeHmTimeInput(value) ?? value)
+  @ApiProperty({ example: '17:00', description: 'HH:mm 24h (17:30 also accepted)' })
   @IsString()
-  @Matches(/^([01]\d|2[0-3]):[0-5]\d]$/)
   endTime!: string;
 }