In Odoo, you can use the datetime module to add 14 days to the current date and set it as the deadline for a task. Here is an example of how you can do it:

import datetime

# Get the current date and time
current_datetime = datetime.datetime.now()

# Add 14 days to the current date and time
deadline_datetime = current_datetime + datetime.timedelta(days=14)

# Set the deadline for the task
record['date_deadline'] = deadline_datetime

In the code above, current_datetime contains the current date and time. We then add 14 days to it using the timedelta method of the datetime module. The resulting deadline_datetime variable contains the date and time 14 days in the future. We then set this value as the date_deadline field of the task.

You can adjust the code to suit your specific needs. For example, you can add a condition to check if the task has reached a specific stage before setting the deadline.