Select Menu > Preferences.
Last updated on
Sep 23, 2025
Learn how to add a trusted timestamp to your PDF in Acrobat to ensure document authenticity and verification.
You can add the date and time to certificate-based signatures or to PDFs without identity-based signatures. Timestamps from a trusted authority help verify when the document was signed and prevent invalidation. They also ensure authenticity and support the PAdES standard (ETSI 102 778).
You can use a timestamp from a third-party authority or your digital ID’s certificate authority. If a timestamp server is set up, its time is used; otherwise, the system's local time is applied. If no timestamp is added during signing, you can apply one later using long-term validation.
Configure a timestamp server and set it as default
Before you begin
Ensure you have a trusted security settings file. If not, ask your administrator for the server name and URL.
Under Categories, select Signatures.
For Document Timestamping, select More.
In the Server Settings dialog box, select Time Stamp Servers from the left pane and then take one of the following actions:
- To import a timestamp server settings file, select Import. When prompted, select the file and then select Open.
- To add a timestamp server URL, select New and then in the dialog box that opens, enter the name and the server URL. Specify whether the server requires a username and password, then select OK.
Select the added timestamp and then select Set Default from the top menu.
In the dialog box that opens, select OK to confirm and then close it.
Apply timestamps to documents
Open the document to which you want to add a timestamp, and then select All tools > Use a certificate.
From the left pane, select Timestamp.
If prompted, save the document to the desired location and rename it if needed.
Once the timestamp is added, a confirmation appears in the Signature Panel at the top.
To view the timestamp details, open the Signature Panel.
