Schedule time error

[stoveup]

When trying to open the schedule tab at 10:59pm:

The above shows up.

[stoveup]

The error only occurs at XX:59; When it becomes XX:00, error does not show up.

[stoveup]

File "C:\Users\szeyi\Desktop\Pythons\CASync\templates\loggedin\schedule.html", line 1, in top-level template code
    {% extends "loggedin/layout.html" %}
  File "C:\Users\szeyi\Desktop\Pythons\CASync\templates\loggedin\layout.html", line 156, in top-level template code
    {% block content %}{% endblock %}
  File "C:\Users\szeyi\Desktop\Pythons\CASync\templates\loggedin\schedule.html", line 102, in block 'content'
    value="{{ now.replace(hour=now.hour+1, minute=now.minute+1).strftime('%Y-%m-%dT%H:%M') }}"
ValueError: minute must be in 0..59

The above error displayed