Help with new (default) templating in 2021.10

Hello guys,
Need help suppressing this warning. Tried to figure out myself using this link from above, but failing.

error:

Template warning: 'strptime' got invalid input '2021-08-27T00:13:16.555' when rendering template '{{ 91 - (( as_timestamp(now()) - as_timestamp(strptime(states.sensor.vj_ssl_cert_issued.state, "%Y-%m-%d")) )/ (3600*24)) | round(0) }}' but no default was specified. Currently 'strptime' will return '2021-08-27T00:13:16.555', however this template will fail to render in Home Assistant core 2022.1

code in question:

value_template: '{{ 91 - (( as_timestamp(now()) - as_timestamp(strptime(states.sensor.vj_ssl_cert_issued.state, "%Y-%m-%d")) )/ (3600*24)) | round(0) }}'