with
t1 as(
    select
        user_id,
        date,
        dense_rank()over(partition by user_id order by date) as uf
    from
        login
),
t2 as(
    select
        date,
        sum(
            case
                when uf=1 then 1
                else 0
            end
        ) as new
    from
        t1
    group by
        date
)
select * from t2 order by date