If you don't want to loose any seminar, click on the link of the Google Calendar you are interested in and then add it to your favorite calendar application (Google Calendar, iCal, etc..).

The content of the different Google Calendars is divided as follows:

APP
APPC APP Colloquium
APPS APP Seminar
APPCoffee APP Coffee
APPPHD APP Ph.D. Defence

AP
APC APP Colloquium
APS AP Seminar
APJC AP Journal Club
APPHD AP Ph.D. Defence
DSML Dennis Sciama Memorial Lecture

TPP
TPPGS TPP Group Seminar
TPPJC TPP Journal Club
JSSEM Joint SISSA/ICTP String Seminar
TPPPHD TPP Ph.D. Defence

Other
SISSAC SISSA Colloquium
HECAPS ICTP HECAP Seminar