Thank you very much for your response. Your point about the getter returning a period object wasn’t known and is well-taken.
I’m using the iso 8601 object as part of an authentication procedure for an API, and I was assuming that simply taking seconds * 1000 would lose some necessary resolution- ie, that it would truncate/ round some info.
A closer look at the ISO specification seems to indicate that there is no millisecond granularity.
So, here’s what I’m attempting for now, similar to your suggestion:
‘my_date_ms_from_epoch <- as.numeric(lubridate::as_datetime(iso_8601)) * 1000 %>% asString()’
If, over the weekend, I find this in fact works, I’ll mark this as solved.
Again, thanks @rensa