CUSTOM VALIDATION FOR DATE OF BIRTH WITH DATA ANNOTATIONS

Here is the code to check whether date is valid or not with date range using custom validation with Data Annotations using C# (ASP.Net MVC)

Step 1: Create a new class with the name DOBDateValidation and inherit ValidationAttribute. ValidationAttribute required System.ComponentModel.DataAnnotations namespace so we need to add “using System.ComponentModel.DataAnnotations;” at the top.

Step 2: Add the following code within the class DOBDateValidation

protected override ValidationResult IsValid(object value,ValidationContext validationContext)
        {
            DateTime date;
            bool parsed = DateTime.TryParse(value.ToString(), out date);
            if (!parsed)
                return new ValidationResult("Invalid Date");
            else
            {
//change below as per requirement
                var min = DateTime.Now.AddYears(-18); //for min 18 age
                var max = DateTime.Now.AddYears(-100); //for max 100 age
                var msg = string.Format("Please enter a value between {0:MM/dd/yyyy} and {1:MM/dd/yyyy}", max, min);
                try
                {
                    if (date > min || date < max)
                        return new ValidationResult(msg);
                    else
                        return ValidationResult.Success;
                }
                catch (Exception e)
                {
                    return new ValidationResult(e.Message);
                }
            }

        }

Here is the complete code.

public class DOBDateValidation : ValidationAttribute
    {
        protected override ValidationResult IsValid(object value,ValidationContext validationContext)
        {
            DateTime date;
            bool parsed = DateTime.TryParse(value.ToString(), out date);
            if (!parsed)
                return new ValidationResult("Invalid Date");
            else
            {
               //change below as per requirement
                var min = DateTime.Now.AddYears(-18); //for min 18 age
                var max = DateTime.Now.AddYears(-100); //for max 100 age
                var msg = string.Format("Please enter a value between {0:MM/dd/yyyy} and {1:MM/dd/yyyy}", max, min);
                try
                {
                    if (date > min || date < max)
                        return new ValidationResult(msg);
                    else
                        return ValidationResult.Success;
                }
                catch (Exception e)
                {
                    return new ValidationResult(e.Message);
                }
            }

        }
    }

Step 3: Use our custom date of birth validator in the Model.

 [Display(Name = "Date of Birth")]
        [DataType(DataType.Date)]
        [DOBDateValidation]
        [Required]
        [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
        public DateTime DOB { get; set; }

Related: Custom Validation for Date with Data Annotations