Invoke-IcingaCheckCertificates - Setting thresholds

I want to test a certificate in the store and get Warning at 1 year to go and Critical with six months to go. I am using Director to set the fields in an Apply Service. The check has defaults of 3 days and 10 days which are not long enough for me. Setting individual numbers doesn’t work because the plugin seems to do a straight compare by value, starting with critical. I get this if I set critical to six months worth of seconds (15552000) and warning at 12 months worth of seconds (31104000) The value here is 1785 days - 154225921 seconds:

CRITICAL … Value “154225921.682124” is greater than threshold “15552000”

This works at the PS on the box (after Use-Icinga):
Invoke-IcingaCheckCertificate -CertStore 'LocalMachine' -CertStorePath 'My' -CertThumbPrint '845C3EA5DE582349FAD4D9662A144EFD10D6382D' -WarningEnd '@15552000:31104000' -CriticalEnd '@0:15552000'

So I tried setting those thresholds in seconds as above in Director and deploying to an agent but that causes the check to give an Unknown output.

Inspecting the service call - this is the invocation which works when I don’t set thresholds:
'C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe' '-C' 'try { Use-Icinga -Minimal; } catch { Write-Output '\''The Icinga PowerShell Framework is either not installed on the system or not configured properly. Please check https://icinga.com/docs/windows for further details'\''; exit 3; }; Exit-IcingaExecutePlugin -Command '\''Invoke-IcingaCheckCertificate'\'' ' '-CertStore' 'LocalMachine' '-CertThumbprint' ''\''845C3EA5DE582349FAD4D9662A144EFD10D6382D'\''' '-CertSubject' '@()' '-CertStorePath' 'My' '-CertPaths' '@()' '-CertName' '@()'

… and this is the inspected invocation when I try to use thresholds in seconds, which doesn’t work - the check gives “Unknown”:
'C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe' '-C' 'try { Use-Icinga -Minimal; } catch { Write-Output '\''The Icinga PowerShell Framework is either not installed on the system or not configured properly. Please check https://icinga.com/docs/windows for further details'\''; exit 3; }; Exit-IcingaExecutePlugin -Command '\''Invoke-IcingaCheckCertificate'\'' ' '-WarningEnd' '@15552000:31104000' '-CriticalEnd' '@0:15552000' '-CertStore' 'LocalMachine' '-CertThumbprint' ''\''845C3EA5DE582349FAD4D9662A144EFD10D6382D'\''' '-CertSubject' '@()' '-CertStorePath' 'My' '-CertPaths' '@()' '-CertName' '@()'

Is this a bug or a misunderstanding on my part?

I came across a bit of documentation that mentions quoting the @ symbol ie `@x:y when used in Icinga. I also noticed an example that used this syntax and that seems to work

-WarningEnd 180d:
-CriticalEnd 90d: