Google Calendar's event reminders become more customizable: “now you can choose any period of time between 5 minutes and 4 weeks”. This works for the default notifications settings, as well individual events. And you can choose to receive notifications by SMS, email and as Google Calendar pop-ups. The default notifications are via email (10 minutes before each event) and pop-ups (5 minutes before each event), but you may need more time.
Tip: to change the notifications settings for a calendar, click on the small arrow next to the calendar's name and select “Notifications”.
In addition , you can also:
Emailing guests: Email meeting attendees, is extremely useful for sharing last-minute details or distributing meeting minutes afterward. But it was an all-or-nothing affair -- if you wanted to email only those people who hadn't responded, for example, you needed to manually fiddle with a list of email addresses.You can now select guests based on their response status or pick-and-choose them individually with checkboxes.
Adding a friend's calendar: Displaying another person's calendar is much easier now: you simply start typing a name in the “Add a friend's calendar” box and we'll match against your address book. Click the name, and the calendar will be added.
Dragging to create new events: Making a new event from the Day or Week view is really easy -- you simply click on the time, drag the duration and enter a name. But if you have a busy calendar (and who doesn't?) you probably bumped into some problems. If an event is already scheduled for that time, there was no way to click and drag without messing up the other events on your calendar. You told us you often worked around this by creating the meeting in an open slot and dragging it to the desired time. Lots of extra work.
Here's proof that little things really do matter -- in this case, just a few pixels. We added a “gutter” to the edge where you can click-and-drag no matter how many events you already have at that time. Check the above screenshot.
Source:→ Google Gmail Blog