Hello @jarikunnel,
I hope you are doing well, and thanks for reaching out. We're sorry for the trouble you had.
Could you please share more details about the issue and the workflow:
Which Adobe Acrobat product and version are you using (A) Acrobat Reader, (B) Acrobat Standard, or (C) Acrobat Pro, and is it the latest release 26.001.21651, Planned update, Jun 05, 2026?
What OS/platform are you using? (A) Windows, (B) macOS.
Are the PDFs separate files that need the same date added, or could they be combined temporarily and then separated again?
What was the source of the PDF file?
Is it a PDF form with form fields or a normal PDF with text?
Please note that if you are using Acrobat's "Edit a PDF" mode, it treats added text as an edit to that specific document's page content, so copy/paste of an edit-mode text box is scoped to the same document.
Suggestions:
Add Header & Footer:
All tools > Edit a PDF > Header & Footer > Add.
Date: The dialog includes an Insert Date button and a Date format dropdown, so the date is inserted as a true date field with a chosen format.
Custom font/size: The dialog provides Font Name and Size controls, plus color and underline — so you can match a specific font and point size.
Apply to many files at once: The dialog has an Apply to Multiple Files (Add Files) option; you add all 15 PDFs and apply the same header/footer in one operation. You can also save the configuration as a named preset for reuse.
To learn more, see this article: https://adobe.ly/4aBQ0qG
Action Wizard/batch:
All tools> Use guided actions (Action Wizard) > create a new action containing an Add Header & Footer (or Bates Numbering) step, then run it against a folder/list of files.
To learn more, see this article: https://adobe.ly/49OeVqX
Bates Numbering:
All tools > Edit a PDF > (More/secondary) Bates Numbering > Add. It can add header/footer text, including a date, across multiple files in one pass. Acrobat Pro only.
Check this article for more details: https://adobe.ly/4vHd4Na
For your immediate 15-file job, use Add Header & Footer with "Apply to Multiple Files." Type the date once, pick your exact font and size, add all 15 PDFs, and apply in a single operation. This is faster and more consistent than copy/paste and gives you the precise font/size control you want.
If the date must appear as free-floating content in arbitrary positions (not header/footer margins), create a Custom Stamp once from a PDF containing your dated text in the desired font/size, then drop it into each file. It persists across sessions, so you only build it once.
If you'll repeat this regularly (e.g., monthly batches), build an Action Wizard action (Acrobat Pro) wrapping the header/footer step so future runs are one click across a whole folder.
Stop trying to copy the Edit-mode text box across files; it is not a supported path and will keep failing. Re-create the text using one of the multi-file tools above.
I hope this helps, and let us know if you need any assistance.
Regards,
Anand Sri.