Remove decimals from resulting datetime

I’m trying to calculate the time since something happened. When I use the following template:

{% set t = now() - (strptime( state_attr('sensor.blah_blah', 'start'), '%Y-%m-%dT%H:%M:%S%z')) %}
{{ t }}

The result is something like: 3:09:00.491679

I have tried piping to timestamp_custom(’%H:%M’) and I get an invalid input error. I’m kind of at a loss for how to remove the decimal and everything after it. It would look a whole lot cleaner in the UI if I could.

{% set t = now() - (strptime( state_attr('sensor.blah_blah', 'start'), '%Y-%m-%dT%H:%M:%S%z')) %}
{{ t.total_seconds() | timestamp_custom('%H:%M', false) }}

You are my hero! I’ve been at this for about an hour and just cant quite get it. This worked perfectly!! Thank you!

You’re welcome!

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