diff --git a/model/end_user_detail.go b/model/end_user_detail.go
index 49ee837..778c35d 100644
--- a/model/end_user_detail.go
+++ b/model/end_user_detail.go
@@ -1,7 +1,9 @@
 package model
 
 import (
+	"context"
 	"errors"
+	"time"
 
 	"github.com/shopspring/decimal"
 	"github.com/uptrace/bun"
@@ -59,6 +61,20 @@ type EndUserDetail struct {
 	Origin                   *Meter04KV          `bun:"rel:belongs-to,join:park_id=park_id,join:meter_04kv_id=code"`
 }
 
+var _ bun.BeforeAppendModelHook = (*EndUserDetail)(nil)
+
+func (d *EndUserDetail) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		d.CreatedAt = oprTime
+		d.LastModifiedAt = &oprTime
+	case *bun.UpdateQuery:
+		d.LastModifiedAt = &oprTime
+	}
+	return nil
+}
+
 func (d EndUserDetail) Validate() (bool, error) {
 	lastPeriodSum := decimal.Sum(d.LastPeriodCritical, d.LastPeriodPeak, d.LastPeriodValley)
 	if lastPeriodSum.GreaterThan(d.LastPeriodOverall) {
diff --git a/model/maintenance_fee.go b/model/maintenance_fee.go
index 89e1850..7ff38fd 100644
--- a/model/maintenance_fee.go
+++ b/model/maintenance_fee.go
@@ -1,6 +1,9 @@
 package model
 
 import (
+	"context"
+	"time"
+
 	"github.com/shopspring/decimal"
 	"github.com/uptrace/bun"
 )
@@ -16,3 +19,17 @@ type MaintenanceFee struct {
 	Memo               *string         `bun:"type:text" json:"memo"`
 	Enabled            bool            `bun:",notnull" json:"enabled"`
 }
+
+var _ bun.BeforeAppendModelHook = (*MaintenanceFee)(nil)
+
+func (f *MaintenanceFee) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		f.CreatedAt = oprTime
+		f.LastModifiedAt = &oprTime
+	case *bun.UpdateQuery:
+		f.LastModifiedAt = &oprTime
+	}
+	return nil
+}
diff --git a/model/meter_04kv.go b/model/meter_04kv.go
index 9ff8fbf..6aac9c4 100644
--- a/model/meter_04kv.go
+++ b/model/meter_04kv.go
@@ -1,6 +1,9 @@
 package model
 
 import (
+	"context"
+	"time"
+
 	"github.com/shopspring/decimal"
 	"github.com/uptrace/bun"
 )
@@ -21,3 +24,17 @@ type Meter04KV struct {
 	Enabled            bool            `bun:",notnull,default:true" json:"enabled"`
 	ParkDetail         *Park           `bun:"rel:belongs-to,join:park_id=id" json:"-"`
 }
+
+var _ bun.BeforeAppendModelHook = (*Meter04KV)(nil)
+
+func (m *Meter04KV) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		m.CreatedAt = oprTime
+		m.LastModifiedAt = &oprTime
+	case *bun.UpdateQuery:
+		m.LastModifiedAt = &oprTime
+	}
+	return nil
+}
diff --git a/model/park.go b/model/park.go
index d6a3916..23a488d 100644
--- a/model/park.go
+++ b/model/park.go
@@ -1,6 +1,7 @@
 package model
 
 import (
+	"context"
 	"time"
 
 	"github.com/jinzhu/copier"
@@ -71,3 +72,17 @@ func FromPark(park Park) ParkSimplified {
 	copier.Copy(&dest, park)
 	return dest
 }
+
+var _ bun.BeforeAppendModelHook = (*Park)(nil)
+
+func (p *Park) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		p.CreatedAt = oprTime
+		p.LastModifiedAt = &oprTime
+	case *bun.UpdateQuery:
+		p.LastModifiedAt = &oprTime
+	}
+	return nil
+}
diff --git a/model/report.go b/model/report.go
index 07f49eb..79191e1 100644
--- a/model/report.go
+++ b/model/report.go
@@ -1,6 +1,7 @@
 package model
 
 import (
+	"context"
 	"time"
 
 	"github.com/uptrace/bun"
@@ -82,3 +83,17 @@ type JoinedReportForWithdraw struct {
 	Park   ParkSimplified       `bun:"extends" json:"park"`
 	User   UserDetailSimplified `bun:"extends" json:"user"`
 }
+
+var _ bun.BeforeAppendModelHook = (*Report)(nil)
+
+func (p *Report) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		p.CreatedAt = oprTime
+		p.LastModifiedAt = &oprTime
+	case *bun.UpdateQuery:
+		p.LastModifiedAt = &oprTime
+	}
+	return nil
+}
diff --git a/model/shared.go b/model/shared.go
index 4b35935..84d2fe0 100644
--- a/model/shared.go
+++ b/model/shared.go
@@ -3,7 +3,7 @@ package model
 import "time"
 
 type Created struct {
-	CreatedAt time.Time `bun:"type:timestamptz,notnull,default:current_timestamp" json:"createdAt" time_format:"simple_datetime" time_location:"shanghai"`
+	CreatedAt time.Time `bun:"type:timestamptz,notnull" json:"createdAt" time_format:"simple_datetime" time_location:"shanghai"`
 }
 
 type CreatedWithUser struct {
@@ -22,7 +22,7 @@ type DeletedWithUser struct {
 
 type CreatedAndModified struct {
 	Created        `bun:"extend"`
-	LastModifiedAt *time.Time `bun:"type:timestamptz,nullzero,default:current_timestamp" json:"lastModifiedAt" time_format:"simple_datetime" time_location:"shanghai"`
+	LastModifiedAt *time.Time `bun:"type:timestamptz,nullzero" json:"lastModifiedAt" time_format:"simple_datetime" time_location:"shanghai"`
 }
 
 type CreatedAndModifiedWithUser struct {
diff --git a/model/user.go b/model/user.go
index 690866d..3420fb7 100644
--- a/model/user.go
+++ b/model/user.go
@@ -1,6 +1,11 @@
 package model
 
-import "github.com/uptrace/bun"
+import (
+	"context"
+	"time"
+
+	"github.com/uptrace/bun"
+)
 
 const (
 	USER_TYPE_ENT int8 = iota
@@ -31,3 +36,13 @@ type UserWithCredentials struct {
 	Type          int8   `bun:"type:smallint,notnull" json:"type"`
 	Enabled       bool   `bun:",notnull" json:"enabled"`
 }
+
+var _ bun.BeforeAppendModelHook = (*User)(nil)
+
+func (u *User) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	switch query.(type) {
+	case *bun.InsertQuery:
+		u.CreatedAt = time.Now()
+	}
+	return nil
+}
diff --git a/model/user_charges.go b/model/user_charges.go
index 86fdef7..70a89fd 100644
--- a/model/user_charges.go
+++ b/model/user_charges.go
@@ -1,6 +1,7 @@
 package model
 
 import (
+	"context"
 	"time"
 
 	"github.com/shopspring/decimal"
@@ -29,3 +30,14 @@ type ChargeWithName struct {
 	UserDetail `bun:"extend"`
 	UserCharge `bun:"extend"`
 }
+
+var _ bun.BeforeAppendModelHook = (*UserCharge)(nil)
+
+func (uc *UserCharge) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		uc.CreatedAt = oprTime
+	}
+	return nil
+}
diff --git a/model/user_detail.go b/model/user_detail.go
index 5c186cf..76969b4 100644
--- a/model/user_detail.go
+++ b/model/user_detail.go
@@ -1,6 +1,7 @@
 package model
 
 import (
+	"context"
 	"time"
 
 	"github.com/jinzhu/copier"
@@ -52,3 +53,17 @@ func FromUserDetail(user UserDetail) UserDetailSimplified {
 	copier.Copy(&dest, user)
 	return dest
 }
+
+var _ bun.BeforeAppendModelHook = (*UserDetail)(nil)
+
+func (d *UserDetail) BeforeAppendModel(ctx context.Context, query bun.Query) error {
+	oprTime := time.Now()
+	switch query.(type) {
+	case *bun.InsertQuery:
+		d.CreatedAt = oprTime
+		d.LastModifiedAt = &oprTime
+	case *bun.UpdateQuery:
+		d.LastModifiedAt = &oprTime
+	}
+	return nil
+}