# Managing Date Formats

The **Date Formats** section allows Administrators to add new date formats and delete date formats that are no longer needed. However, Admins cannot delete default date formats of **Cryoserver**.

The format of the date header in every email is well defined by the RFC822 standard. However, some email clients and mail generation systems do not follow the RFC822 standard, resulting in a wide range of date formats. **Cryoserver** tries to handle all of the variations that have been detected over many years.

**Cryoserver** will always try to obtain the date from the standard email “Date:” header. If this fails then it will try to obtain the date from the topmost “Received: from” header.

However the Received: from header date/time will be slightly different to the Email date/time, i.e., some email matching services (like Stubbing) may fail to accurately locate an email in **Cryoserver** if the Received: from date/time is used by default. If **Cryoserver** cannot determine the date from the email headers, it will raise an error.

If you know that some internal mail generation service creates emails with a particular non-standard format, then you can add its format here.

Pattern letters are usually repeated. The number of repeats determines the exact presentation:

{% hint style="info" %}

* Text: For formatting, if the number of pattern letters is 4 or more, the full form is used; otherwise a short or abbreviated form is used if available. For parsing, both forms are accepted, independent of the number of pattern letters.
* Number: For formatting, the number of pattern letters is the minimum number of digits, and shorter numbers are zero-padded to this amount. For parsing, the number of pattern letters is ignored unless it's needed to separate two adjacent fields.
* Year: For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted as a number.
  {% endhint %}

### Updating

1. Navigate to **Adv Configuration** > **Date Formats**.
2. To add a new date format, enter the format in the textbox, click the **Add** button, and then click the **Save** button. The new date format will be added.
3. To delete a user added date format, click the date format and then click the **Delete** button. The select date format will be deleted.
4. To test date parsing, click the **Test Date Parsing** button.
5. To test date format using an existing format, select **Existing Formats** option, enter the test date string, and then click the **Test** button.
6. To test date format using a new format, select **New Format** option, enter the new format and test date string, and then click the **Test** button.


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