When I delete old appointments in the calendar, they disappear until I close it. They show up in the calendar the next time I open it though.

when in itunes look at the iphone page, click on calandar on the tabs on top, when you see that click "dont sync" that should do it.

plz refer to the manual, if you dont have then you give your mobile make and model no

uninstall office, restart pc and reinstall office

Make sure time-zone is the same for both iPhone and the computer.

On iPhone setting > Mail,Contacts,Calendars setting > Time Zone Support, make sure you are choosing the city where you are in.

Otherwise, make sure you have updated the iTunes to 7.5 or later.

Update to iTunes 7.5 or later to resolve this issue. If you're not able to update, continue reading for other options to resolve the issue.
Each Outlook calendar event has an internal property known as "Message Class." When some Outlook plug-ins are installed (such as Live Search Maps), the setting for the Message Class property can change from its default of "IPM.Appointment" to something else. iPhone and iPod touch are only able sync calendar events with the Message Class set to "IPM.Appointment," therefore any calendar events created after installing certain Outlook plugins may no longer sync.
To verify this, examine the property of the Calendar event items for MS Outlook and see if the Message Class shows something other than "IPM.Appointment" in any of the calendar events. To view the Message Class property for your Outlook Calendar events, add the Message Class field as one of the columns in the Current View using these steps:

1. Open Outlook Calendar on the computer.
2. Choose View > Current View > Events.
3. For Windows Vista, choose View > Current View > Customize Current View.
   For Windows XP, choose View > Arrange By > Current View > Customize Current View.
4. Click the Fields button and choose All Appointment fields from the pop-up menu in the "Select available fields from" section.
5. In the "Available Fields" column, select "Message Class" and click the Add button.
6. Click OK.
7. Click OK.

Now verify that all your calendar events are showing "IPM.Appointment" for the Message Class column. If you have calendar events showing a different value other than "IPM.Appointment" you will need to perform the following steps to fix the issue.

1. Uninstall any Outlook plugins such as Live Search Maps or other plugins which change the default Message Class "IPM.Appointment" to some other value. Once the plugins have been removed, verify if those calendar events revert back to the Message Class of "IPM.Appointment" so that you can sync the calendar data to iPhone/iPod touch. If you are able to sync, try adding the plugins back one at a time and verify that you are still able to sync.
2. If removing the Outlook plugins does not change the Message Class value for the calendar events, manually change the Message Class value of those calendar events to "IPM.Appointment." For more information on Message Class and how to change the Message Class fields/value, refer to Microsoft's KB article 201087 How to update existing items in an Outlook folder to use a new custom form

Good luck!

Set your appointment through your calendar. It will indicate when you wished to be notified and how long you want to be notified. If your worried about the sound of the alert when you receive your appointment notification, then change the default sound within your settings.

I have a lot of problems with the calender. when I first got the phone, a week or two ago, I put my work houres in it, and the whole week, no alarm. then weekend came and a small icon above of a small calender appeared, and the whole weekend it kept on going off 5 times in a row at 7.30, the time I needed to leave for work in the week, when it didnt went off at all O_o today, I had to leave at 8.30 and it went off at 8.30 but also at 7.30 again, while that's not an alarm in my calendar for today.. after work my cookie suddenly went out, I had to take the battery pack out to "reboot" it, now the calender icon is gone, I wonder if it will go off at 8.30 tomorow like planned or if it won't go off at all anymore again..
Another thing I noticed is, that when I put in a date from one houre to another is that it doesn't state the correct houre (when I put in 8.00 to 16.00 it shows 00.00 to 16.00) I put in until I open the actual appointement.
strangely enough, my cookie just lighted up it's screen as if I touched it out of itself and even more strange, the calendar icon up there is back..!

no you can not....you will need to delete old meetings and dates on your calendar

To add, change, or delete a Calendar appointment from the handheld, follow these steps: To add an appointment

1. From the Home screen, press the Menu key.
2. Scroll to and select Calendar.
   • NOTE: To select, press the trackball.
3. Scroll to and select desired date and time.
   • NOTE: Selecting exact date and time will default to that date and time when the appointment opens, however these fields can be changed so any date and time can be selected.
4. Enter a Subject.
5. Enter a Location.
6. If desired, select All Day Event.
7. If desired, scroll to and set the Start and End date and time.
   • The 'Duration' should update accordingly.
8. Scroll to and set Time Zone as desired.
9. Scroll to Show Time As.
10. Select one of the following as desired:
    • Free
    • Tentative
    • Busy
    • Out of Office
11. Scroll to and set Reminder time as desired.
    • The options range from None to 1 Week.
12. Scroll to and set Recurrence as desired:
    • None
    • Daily
    • Weekly
    • Monthly
    • Yearly
13. If desired, select Mark as Private.
14. If desired, select Notes, then type any notes.
15. Press the Escape key.
16. Select Save.

To change an appointment

1. From the Home screen, press the Menu key.
2. Scroll to and select Calendar.
   • NOTE: To select, press the trackball.
3. Select the appointment to be changed.
4. Adjust any options as desired.
   • NOTE: The available appointment options are listed in the portion above.
5. Press the Escape key.
6. Select Save.

To delete an appointment

1. From the Home screen, press the Menu key.
2. Scroll to and select Calendar.
   • NOTE: To select, press the trackball.
3. Select the appointment to be deleted.
4. Scroll to and select one of the following:
   • Open the series (for reoccurring appointments)
   • Open this occurrence
5. Press the Menu key.
6. Select Delete.
7. Select Delete again to confirm.

I would recomend that you powercycle your phone regularly. If you have anymore questions feel free to ask me.

Try to Run this command

Start > Run > Outlook /cleanreminders

yes the default is that the ipaq only keeps the past two weeks. To change this, open Activesync on PC, double click on Calendar.