Lost all calendar entries after upgrade to iPhone OS 4.0.

When I upgraded my OS to 4 on my iPhone 3G and lost all my calendar entries on my phone. After checking on Google calendar, I found they are all gone there too. I'm wondering if my local calendar got zapped somehow and then uploaded to Google calendar. Is this possible? Is there any way to a) find my data or b) figure out what happened?

Please help. This is very distressing as I'm very reliant on my calendar.

Best Regards,
April

aprilslade wrote:When I upgraded my OS to 4 on my iPhone 3G and lost all my calendar entries on my phone. After checking on Google calendar, I found they are all gone there too. I'm wondering if my local calendar got zapped somehow and then uploaded to Google calendar. Is this possible? Is there any way to a) find my data or b) figure out what happened?

Hi April, I sent you a longer reply in email but the short answer is that this isn't possible (for an iPhone to 'zap' both its local calendar and sync the zapping over to Google).
At least, there's no mechanism that we know of that can lead to that happening, and nobody besides you has ever reported seeing this happen with an Apple device.
Another strange thing about this is that the calendar is not normally touched in the update to iOS4. The same calendar content should be present after the update.

One thing to note is that Apple devices (iPhone, iPad, iPod touch) are designed to delete or move into a special group (the user is asked which they want) any existing data when sync is setup.
So it's not surprising to have no calendar events on the phone after configuring sync (if the option to delete is selected). But this doesn't in any way affect the data stored at Google.
The only reason our service ever deletes an event stored at Google is when the phone specifically asks it to do so (e.g. the user deletes the event on the phone).

A couple of suggestions:

1. See if you can restore your phone from a backup in iTunes. Apple has some information about this here : http://support.apple.com/kb/ht1766
Unfortunately if you haven't taken steps to retain the old iTunes backup files, it will only keep the most recent one (which may not have the data you need).

2. Check that the events are really not at Google. Sometimes Google's calendar site doesn't load the events, making it look like they've vanished, but they're still stored there. Refreshing the page will often bring them back if that's the case.