I suggest this calendar for 2013, but we need someone for rankings
14.01 - Australian Open
28.01 - Davis Cup First Round
18.02 - Memphis/Marseille/Buenos Aires
04.03 - Indian Wells
18.03 - Miami
01.04 - Davis Cup QF
15.04 - Monte Carlo
22.04 - Barcelona/Bucharest
06.05 - Madrid
13.05 - Rome
27.05 - Roland Garros
03.06 - Halle/Quenns
24.06 - Wimbledon
15.07 - Atlanta/Hamburg
05.08 - Montreal
12.08 - Cincinnati
26.08 - US Open
09.09 - Davis Cup SF
30.09 - Beijing/Tokyo
07.10 - Shanghai
21.10 - Basel/Valencia
28.10 - Paris
04.11 - London Masters
11.11 - Davis Cup Final