Epoch time validation in marshmallow

Hi,
I want to validate epoch time . Is there any way to do this using marshmallow. I will be getting this in request body . Dont know which format to be used .
```
 Time example: 1568783919
```

The issue does not name a file, test, or entry point; begin by reviewing marshmallow's field and validation documentation for request-body values. Determine whether epoch time is already supported and document the accepted format or validation approach, with an example using 1568783919. Done means a newcomer can identify the appropriate field and validate this value.

Written by the indexing model from the issue text.