restoring calendar entries saved on the iphone

To restore your calendar events, add the email account to your device again and ensure that the Calendar option is enabled in the account settings. Once the account is successfully added and synchronisation is complete, all calendar events associated with that account should reappear automatically. You generally do not need to add the events manually.

However, there is an important exception. If the email account belongs to an organisation, school, college, or enterprise that you have since left, recovering those events may not be possible if your access to the account has been revoked. In such cases, you will no longer be able to sign in to the account to synchronise or retrieve the associated calendar events.

Your ability to recover those events will depend on the organisation's account-retention policies and whether the data is still available. If necessary, contact the organisation's IT administrator to request access to your calendar data or ask whether a copy can be exported and provided to you.

In short: If you still have access to the email account, re-add it and enable Calendar synchronisation. If you have lost access to an organisational account, you may need the organisation's assistance to recover your calendar events.