Maybe something like this might help.
Note that there's commented code that you might need to use to get the correct results.
CREATE TABLE ##Counts(
Table_Namenvarchar(128),
Whendate,
RecCount int --bigint
)
DECLARE @SQL nvarchar(MAX)= ''
SELECT @SQL = @SQL + 'INSERT INTO ##Counts
SELECT ''' + TABLE_NAME + ''' '+ TABLE_NAME + ',
When, --DAETADD( dd, DATEDIFF( dd, 0, When), 0)
COUNT(*)
FROM [' + TABLE_SCHEMA + '].[' + TABLE_NAME + ']
GROUP BY When --DAETADD( dd, DATEDIFF( dd, 0, When), 0)' + CHAR(10)
FROM INFORMATION_SCHEMA.tables
EXEC( @SQL)
SELECT * FROM ##Counts