If you want to apply conditional validation on 'Birth Year' or 'Admission Date', then you need to add 'Name' input as 'Bharat'
{{userFormGroup.controls.name.errors.leapYear.message}}
To apply the validation of leap on 'Admission Year' field, then enter the value 'Bharat' in 'Name' textbox
Conditional Expression with type 'string'
{{userFormGroup.controls.admissionYear.errors.leapYear.message}}
To apply the validation of Leap Year on 'Birth Year' field, then enter the value 'Bharat' in 'Name' textbox
Conditional Expression with type 'function'
{{userFormGroup.controls.birthYear.errors.leapYear.message}}