I am working on a custom calendar tab that an area would use to see vehicles that have been scheduled, medical appointments, therapy appointments, other non-medical appointments. I love that you can create color coded calendars (i.e. medical is red scheduled vehicles are blue etc). I have two questions: 1. Is there a way to turn the colored calendars on and off. I.E. You click a check box of the calendars you want to see on the calendar? 2. I have a custom birthday field on the “Person Account” object that calculates the next birthday based on the clients date of birth. Is there anyway to automatically grab that date and put it on the calendar so all client birthdays are listed on the calendar?

1. We currently don’t have a way of turning off model sources in calendars.  We have idenitifed this as a calendar improvement idea. 
2. Currently the items to be shown on a calendar needs to be a date time field. If you change your birthday field to be a date time field you can use it in a calendar.   This is also an improvement option currently being considered. 

I think a date only field, viewed as an “All Day” type event would add a ton of functionality as you could calendar any date field. For anyone who is interested, I did a workaround on the birthday. I encased my next birthday date formula (calculated off of date of birth) in a datetimevalue() function which converts the date into a datetime output and switched my field type to datetime. This works, however, this function sets the time to GMT and so depending on your timezone the birthdays show up a day early. . . To solve this I added +0.5 which I believe adds 12 hours to the time. I.e. Half a day. I currently have set my start time and stop time to this datetime field. This means it shows up on the calendar “month” view just great. But it is just a sliver in the morning on the “week” and “day” view and it’s exact time would change based on the users time zone. If you wanted it to show up for a longer period of time, like an hour, you would have to create one more formula field to calculate an end time and add an hour to the previous calculation so it would span more time. It is not a perfect solution but it works as a bandaid to at least show a date field on the calendar. datetimevalue(IF ( MONTH ( Date_of_Birth__c )=2 && DAY (Date_of_Birth__c)=29, IF ((DATE (YEAR(TODAY()),1,1) + 59) > TODAY(), (DATE (YEAR(TODAY()),1,1)) + 59, (DATE (YEAR(TODAY())+1,1,1)) + 59), IF (DATE (YEAR(TODAY()),MONTH(Date_of_Birth__c),DAY(Date_of_Birth__c)) > TODAY(), DATE (YEAR(TODAY()),MONTH(Date_of_Birth__c),DAY(Date_of_Birth__c)), DATE (YEAR(TODAY())+1,MONTH(Date_of_Birth__c),DAY(Date_of_Birth__c)) ) ))+0.5

One more positive comment. The ability to add whatever fields and text to the “Event Display” through the “Event Template” is awesome!! It allows my users to see all pertinent information at a glance without hovering or clicking. It is functionality that even the calendaring apps are not allowing. It appears most of those I have looked at are only showing the one line subject. Thanks for a great feature!