Thank you Kingston and Drew,
you are right in SQL Server there are datetime data types with functions designed for this kind if data. yyyymmdd as int would not make sense, like date as varchar.
Things might change if I need to transfer the data from/to another system, non SQL Server, for example using CSV file, this yyyymmdd might be useful in this case, I am thinking that this yyyymmdd int would help me not to lose date wile transfering.
But for operational databases and for user inputs I absolutely agree with you.