Todays latest and yesterdays latest record

I have a table with code and Date

Code         Date  
----------------------------
A1           21 May 2015 15:47
A2           21 May 2015 10:30
A3           20 May 2015 10:30
A4           21 May 2015 10:30
A1           19 May 2015 15:20
A2           21 May 2015 12:30
A3           19 May 2015 05:30
A4           18 May 2015 15:38
A1           19 May 2015 05:30
A2           20 May 2015 05:30
A3           21 May 2015 05:30
A4           21 May 2015 05:30
A3           21 May 2015 06:30
A1           21 May 2015 05:30

I need to get the Todays latest record, and yesterdays latest record of A1,A2,A3,A4 showing like below

Flag         Code         Date
-----------------------------------------
Today         A1       21 May 2015 15:47
Today         A2       21 May 2015 10:30
Today         A3       21 May 2015 06:30
Today         A4       21 May 2015 10:30


Yesterday     A1        -- 
Yesterday     A2       20 May 2015 05:30
Yesterday     A3       20 May 2015 10:30
Yesterday     A4        --

Help me how to write query to get data