diff --git a/openapi.json b/openapi.json
index 6fe40e4..2c30cf8 100644
--- a/openapi.json
+++ b/openapi.json
@@ -1,5 +1,5 @@
 {
-  "hash": "0d281cd06010165c6b9979c2c30e2f98b9c6eb6cc5c49a1d2374ddd3397883e0",
+  "hash": "a499cd3dde02dd82d308aa0d3fcd3f082c1ee0cb50da627a71c9257fa5083fc4",
   "openapi": "3.0.0",
   "paths": {
     "/hello": {
@@ -6270,6 +6270,17 @@
                 "createdAt"
               ]
             }
+          },
+          "dateUnit": {
+            "type": "string",
+            "description": "Date unit for time-based grouping when createdAt is in group",
+            "enum": [
+              "hour",
+              "day",
+              "week",
+              "month",
+              "year"
+            ]
           }
         }
       },
diff --git a/src/user/dto/aggregate.dto.ts b/src/user/dto/aggregate.dto.ts
index c40a9ab..a512e2b 100644
--- a/src/user/dto/aggregate.dto.ts
+++ b/src/user/dto/aggregate.dto.ts
@@ -13,6 +13,14 @@ export enum GroupField {
   createdAt = 'createdAt',
 }
 
+export enum DateUnit {
+  hour = 'hour',
+  day = 'day',
+  week = 'week',
+  month = 'month',
+  year = 'year',
+}
+
 export class AggregateUserDto {
   /**
    * The group by clause
@@ -20,4 +28,11 @@ export class AggregateUserDto {
   @IsOptional()
   @IsEnum(GroupField, { each: true })
   group?: GroupField[];
+
+  /**
+   * Date unit for time-based grouping when createdAt is in group
+   */
+  @IsOptional()
+  @IsEnum(DateUnit)
+  dateUnit?: DateUnit;
 }
diff --git a/src/user/user.service.ts b/src/user/user.service.ts
index 3d133c0..9dc0fbe 100644
--- a/src/user/user.service.ts
+++ b/src/user/user.service.ts
@@ -8,7 +8,7 @@ import { createHash, validateHash } from 'src/lib/crypt';
 import { countTailZero, inferNumber } from 'src/lib/lang/number';
 import { buildMongooseQuery, genAggGroupId, genSort, unWindGroupId } from 'src/mongo';
 
-import { AggregateUserDto } from './dto/aggregate.dto';
+import { AggregateUserDto, DateUnit, GroupField } from './dto/aggregate.dto';
 import { CreateUserDto } from './dto/create-user.dto';
 import { ListUsersQuery } from './dto/list-users.dto';
 import { UpdateUserDto } from './dto/update-user.dto';
@@ -180,8 +180,23 @@ export class UserService {
    */
   aggregate(query: ListUsersQuery, dto: AggregateUserDto): Promise<UserAggregateResult[]> {
     const { filter, offset, limit, sort } = buildMongooseQuery(wrapFilter(query));
-    const { group = [] } = dto;
-    const groupId = genAggGroupId(group);
+    const { group = [], dateUnit = DateUnit.day } = dto;
+
+    // 处理时间字段分组
+    let groupId: any = {};
+    const hasCreatedAt = group.includes(GroupField.createdAt);
+
+    if (hasCreatedAt) {
+      // 分离出非时间字段
+      const nonTimeFields = group.filter((field) => field !== GroupField.createdAt);
+      // 为时间字段生成特殊的分组ID
+      groupId = {
+        ...genAggGroupId(nonTimeFields),
+        createdAt: this.getDateGroupExpression(dateUnit),
+      };
+    } else {
+      groupId = genAggGroupId(group);
+    }
 
     // 特殊字段需要先进行 $unwind
     const unwindFields = ['labels', 'groups', 'roles'];
@@ -218,4 +233,44 @@ export class UserService {
 
     return this.userModel.aggregate(pipeline);
   }
+
+  private getDateGroupExpression(dateUnit: DateUnit) {
+    const dateExpression = '$createdAt';
+
+    switch (dateUnit) {
+      case DateUnit.hour:
+        return {
+          year: { $year: dateExpression },
+          month: { $month: dateExpression },
+          day: { $dayOfMonth: dateExpression },
+          hour: { $hour: dateExpression },
+        };
+      case DateUnit.day:
+        return {
+          year: { $year: dateExpression },
+          month: { $month: dateExpression },
+          day: { $dayOfMonth: dateExpression },
+        };
+      case DateUnit.week:
+        return {
+          year: { $year: dateExpression },
+          week: { $week: dateExpression },
+        };
+      case DateUnit.month:
+        return {
+          year: { $year: dateExpression },
+          month: { $month: dateExpression },
+        };
+      case DateUnit.year:
+        return {
+          year: { $year: dateExpression },
+        };
+      default:
+        return {
+          year: { $year: dateExpression },
+          month: { $month: dateExpression },
+          day: { $dayOfMonth: dateExpression },
+        };
+    }
+  }
 }