Using the Japanese concept of HONYAKUSURU, you are able to decipher that the odd symbols at the top of the calendar roughly translate to the American concept of 'JULY'.

You've marked your birthday, the 2nd of July. Another day you marked was supposed to be the arrival date for the highly touted SBURB BETA LAUNCH, though it wouldn't show here as it was on the 30th of June.

It's been three days already. It's starting to become a sore subject with you.