How to get start and end date from month number and Year in sql server

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declare @Year int=2020, @Month int=1

Select 'Month Name : '+ DateName( month , DateAdd( month , @Month , 0 ) - 1 )

select cast(dateadd(month, @Month - 1, dateadd(year, @Year - 1900, 0)) as date) [Start Date],

       cast(dateadd(month, @Month,dateadd(year, @Year - 1900, -1)) as date) [End Date]

////////////////// Result

Month Name : January

Start Date End Date

2020-01-01 2020-01-31