当类型为time.Weekday时，如何通过邮递员获取struct变量的值？

Here I have a struct in golang codegiven below:-

type Schedule struct{
 Id           int                 `json:"_id" bson:"_id"`
 Day          time.Weekday        `form:"day" json:"day" bson:"day"`
 StartDate    int64               `form:"start_date" json:"start_date" bson:"start_date"`
 EndDate      int64               `form:"end_date" json:"end_date" bson:"end_date"`
 StartTime    int64               `form:"start_time" json:"start_time" bson:"start_time"`
 EndTime      int64               `form:"end_time" json:"end_time" bson:"end_time"`
 AddedOn      int64                `form:"added_on" json:"added_on" bson:"added_on"`
 Occurence    string               `form:"occurence" json:"occurence" bson:"occurence"`
 UpdatedOn    int64                `form:"updated_on" json:"updated_on" bson:"updated_on"`
}

Here is the route when I hit the route then it will call a function given below:-

 Route{"SaveData", "POST", "/schedule", controller.SaveData},

SaveData function:-

func SaveData(c *gin.Context) {
    schedule.Day = c.PostForm("day")
    fmt.Println(schedule.Day)
}

#Error is :- cannot use c.PostForm("day") (type string) as type time.Weekday in assignment

Type of Weekdays I want to save :-

 type Weekday int

 const (
   Sunday Weekday = iota
   Monday
   Tuesday
   Wednesday
   Thursday
   Friday
   Saturday
 )

How will I save the weekday in the database using postman. Any help is appreciated. Thank you.