The tl;dr of this is that when julia does DateTime parsing, it tends to cast any resulting int values to Int64 (year, month, day, etc). Specifically on the “u” or “U” dateformat (which is either abbreviated month i.e. jan, or full month name i.e. January) julia will return an Int32 on 32-bit machines as that code path does not cast the result to an Int64.
I have more details in the following link to an issue, but I will copy/paste the important parts here as well
Specifically this line https://github.com/JuliaLang/julia/blob/a7fabc91638064ebbad03831881b1459d4b92bd5/stdlib/Dates/src/query.jl#L73
valueshould be something like
value::Int64. On 32 bit systems, this will return as a 32 bit value and will fail at this function https://github.com/JuliaTime/TimeZones.jl/blob/master/src/types/zoneddatetime.jl#L121 since it expects all inputs to be Int64
I’ll note that the other non lookup conversion values (year, month, day) they get casted to an Int64 https://github.com/JuliaLang/julia/blob/a7fabc91638064ebbad03831881b1459d4b92bd5/stdlib/Dates/src/parse.jl#L163 so it seems like the text version of the month is the only value that this problem exists for.
A 32-bit value is also returned for DoW conversions as it follows a similar path as the month conversions.
I wasn’t sure if this really warranted a bug issue on github, so I figured I’d bring it here first to see if anybody had any thoughts on it.