EDIT: Comigo não funcionou =SXDADEVELOPERS - yc1437:did you try "calendar notifier" search the market its free and you can use any ringtone set it to vibrate also and best of all it can repeat at set intervals for say % times so you wont miss it .
Caso alguém saiba mais alguma solução partilheFor rooted phone, u can replace 22_on_time.ogg to other audio file u want (with same file name), 22_on_time.ogg is the audio played by calendar notification. This file located at /system/media/audio/notifications