How to change content output from db in templarte?

Question

Django

There is a request from a DB where 5 objects come:
I display in the for loop.
But time comes in UNIX format (ex. 15561253451), I want to get str format.

{% extends 'user/template.html' %}

{% block content %}
    {% for signal in signals %}
        {{ signal.close_time }}
    {% endfor %}
{% endblock %}

Something like this:

{% extends 'user/template.html' %}

{% block content %}
    {% for signal in signals %}
        {{ datetime.utcfromtimestamp(signal["close_time"]).strftime('%Y-%m-%d %H:%M:%S') }}
    {% endfor %}
{% endblock %}