There is an issue with the calendar reminders, that is when you have an 'all day event' then the device would wake up at 12:00 AM to remind you. For some people it might be ok but most of us want device to show the reminder at some convenient time (such as 08:00 AM when having a coffee).

This small utility will allow you to mass update all such events to some fixed time span. That is converting all these all day events to non all day with the option to set your own time span.

It also has a command line interface so if you want to automate this process you could do it as follows. Watch the format above and space between the two times specified. For the reminder update just supply the reminder time in hours such as 13 hours in the below example.
Code:
To Full day to non full day --> \Program Files\rk-Calendar-Update.exe "08:00" "22:00"
To just change the reminder time(in hours) --> \Program Files\rk-Calendar-Update.exe 13

Important notes:

• Utility would convert the actual events to fixed time events permanently. So when synchronize with your desktop PC changes applied back to your PC and all your all day events have been changed to fixed time! If that is acceptable use this app.
• I have tested it only on Hermes/WM6 so you test it on your devices (I will recommend some kind of backup before running it just in case).
• I have seen some of the events did not convert right away when there is a conflict in appointments. But running the utility again converted all successfully.
• You can run this update any number of times, it only updates the full day events if found.

Update Description:
v1.0.1:
- Now the application also updates all All Day Event's default reminder time as per your requirement.
- Choose your reminder hours from the new tab added and update all All day events.