"Anton Jiranek died in August 1920 at age 80 and the census should have been taken in April or June, so he should be there."

As you are probably aware by now, the 1920 Census was somewhat unique in that it commenced on 1 Jan 1920. I recall reading somewhere that the rationale was to facilitate a more thorough documentation of rural, agrarian families who would normally be very heavily involved in farm-associated activity in the early spring.

You can read a bit more at...

https://wiki.familysearch.org/en/United_States_Census_1920