Problems Using Alexa Media Player timestamps to trigger automation

My goal is to take the time stamp from sensor.master_bedroom_echo_show_next_alarm - states(sensor.date_time) [or another version: utc ect…] and then have an automation that triggers an input_boolean switch when it reaches 00:01. That input_boolean will intern be used as a condition in various automations that are trigger by an IFTTT webhook when my Alexa alarm goes off. By doing this I can make sure that [example] the coffee pot is only turned on when the master bedroom alexa alarm goes off as apposed to the guest bedroom dot.

Right now

{{ states('sensor.master_bedroom_echo_show_next_alarm') }}
produces a result of 2020-07-04T14:53:00-05:00
This seems like a mix of iso and utc formatting.
I have tried encasing the above in a Strptime and then subtract the sensor.date_time
{{ strptime(states.master_bedroom_echo_show_next_alarm),'%Y-%m-%dT%H:%M:%S%z')-states('sensor.date_time') }}
This just errors out. Any idea how to correctly extract time from the next_alarm and subtract it from current time?