To change the date of a meeting on an Outlook calendar drag the meeting to the desired date. If the desired date is not visible you can double-click the meeting to open a dialog box which should have a drop-down calendar available in the leftern start time box.
To prevent any changes being sent out as updates you will need to set Outlook to offline by selecting the Work Offline button under the Send/Receive tab. In older versions this can be found under the File menu. Alternatively, remove the computer from the network. Afterwards, simply edit the meeting as normal and hit the Send Update button. Proceed to the outbox and delete the meeting update. Make sure to set Outlook back to working online.