SQL Server 2019

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Microsoft SQL Server 2019 (RTM-CU3) (KB4538853) - 15.0.4023.6 (X64) Mar 4 2020 00:59:26 Copyright (C) 2019 Microsoft Corporation Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)

declare @t table (Header int, FPSNs int, TotalSNs int, StartTime datetime)
insert into @t select 2082, 6, 6, '2020-04-08 10:30:02.000'
insert into @t select 2085, 6, 6, '2020-04-08 15:42:18.000'
insert into @t select 2088, 0, 3, '2020-04-08 19:00:22.000'
insert into @t select 2234, 1, 4, '2020-04-08 06:04:01.000'
insert into @t select 2081, 4, 4, '2020-04-09 21:32:27.000'
insert into @t select 2082, 5, 7, '2020-04-09 13:33:51.000'
insert into @t select 2085, 3, 6, '2020-04-09 07:53:34.000'
insert into @t select 2088, 1, 4, '2020-04-09 17:21:27.000'
insert into @t select 2082, 6, 6, '2020-04-14 15:00:08.000'
insert into @t select 2223, 7, 8, '2020-04-14 06:41:47.000'
insert into @t select 2082, 10,12,'2020-04-15 08:32:20.000'
insert into @t select 2085, 5, 5, '2020-04-15 11:10:16.000'
insert into @t select 2234, 3, 4, '2020-04-15 12:24:13.000'
insert into @t select 2260, 4, 5, '2020-04-15 10:16:44.000'

drop table if exists #final

CREATE TABLE #final (Header varchar(max), Result varchar(max), startdate date, rc int);

INSERT INTO #final
SELECT t.Header
      ,CONVERT(varchar(10),FPSNs) + '/' + CONVERT(varchar(10),TotalSNs) as Result
--    ,LEFT(DATENAME(WEEKDAY,StartTime),3) as 'Day'
      ,convert(date, StartTime) as Startdate
	  ,rc
FROM @t t
join
(
	select count(1) rc, Header from @t group by Header
)x on x.Header = t.Header

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX);

SET @cols = STUFF((SELECT distinct ',' + QUOTENAME([Startdate]) 
            FROM #final
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)')
        ,1,1,'')

SET @query = 'SELECT Header, ' + @cols + 'FROM
	(
		SELECT Startdate, header, Result, rc from #final
	) p
	PIVOT
	(
		MAX(Result) For Startdate in ( ' + +@cols + ')
	)AS pvt
	order by rc desc';
execute(@query)

Header	2020-04-08	2020-04-09	2020-04-14	2020-04-15
2082	6/6	5/7	6/6	10/12
2085	6/6	3/6	null	5/5
2088	0/3	1/4	null	null
2234	1/4	null	null	3/4
2081	null	4/4	null	null
2223	null	null	7/8	null
2260	null	null	null	4/5