Grouping By A Formated Column

I have a date column that formated and i need to group by it, how do it do this? i get this error code:

Msg 8120, Level 16, State 1, Line 2
Column 'o.Initials' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

here is my query:
select * from(
SELECT CONVERT(VARCHAR(10), AITDate, 110) AS FormatDate
, TechInt as Initials
, [Drug]
,[Missed PT Notes]
,[Pt Same Name]
,[PT Family]
,[Wrong PT]
,[Wrong Ques. Asked]
,[DAW]
,[Rx/Refills Omitted]
,[Allergy]
,[Wrong Sig]
,[Strength]
,[Wrong PT Address]
,[Quantity]
,[SVQ]
,[Refills]
,[Write Date]
,[Wrong MD/MD Info]
,[Rx Should be Questioned]
,[TSTF],[Non-Link Image]
,[DC Date],[Days Supply]
,[No Call Card]
,[Order Count]
,[Credit Hold Procedure]
,[Routing]
,[Sig Typo]
,[Verse Missing/Wrong]
,[Right Drug Wrong Form]
,[Others]
from tblaitinfo
pivot (count(ercode) for ercode in ([Drug],[Missed PT Notes],[Pt Same Name],[PT Family],[Wrong PT],[Wrong Ques. Asked],[DAW],[Rx/Refills Omitted],[Allergy],[Wrong Sig],[Strength],[Wrong PT Address],[Quantity],[SVQ],[Refills],[Write Date],[Wrong MD/MD Info],[Rx Should be Questioned],[TSTF],[Non-Link Image],[DC Date],[Days Supply],[No Call Card],[Order Count],[Credit Hold Procedure],[Routing],[Sig Typo],[Verse Missing/Wrong],[Right Drug Wrong Form],[Others])) p
)o
group by formatdate