I use this:
- platform: snmp
host: !secret unifi_bonus_switch
name: Bonus Room Switch Uptime
baseoid: 1.3.6.1.2.1.1.3.0
value_template: >
{%- set time = value | int // 100 %}
{%- set minutes = ((time % 3600) // 60) %}
{%- set minutes = '{}min'.format(minutes) if minutes > 0 else '' %}
{%- set hours = ((time % 86400) // 3600) %}
{%- set hours = '{}hr '.format(hours) if hours > 0 else '' %}
{%- set days = (time // 86400) %}
{%- set days = '{}d '.format(days) if days > 0 else '' %}
{{ 'Less than 1 min' if time < 60 else days + hours + minutes }}
Looks like this:

EDIT: Sorry, thought you were snmp.
This is the same thing that I use for uptime on my APC. It’ll have the same look.
sensor:
- platform: template
sensors:
ups_uptime:
entity_id:
- sensor.time
value_template: >
{%- set time = states('sensor.ups_battery_backup_battery_runtime') | int %}
{%- set minutes = ((time % 3600) // 60) %}
{%- set minutes = '{}min'.format(minutes) if minutes > 0 else '' %}
{%- set hours = ((time % 86400) // 3600) %}
{%- set hours = '{}hr '.format(hours) if hours > 0 else '' %}
{%- set days = (time // 86400) %}
{%- set days = '{}d '.format(days) if days > 0 else '' %}
{{ 'Less than 1 min' if time < 60 else days + hours + minutes }}