I don’t know if this is intended or not, but date parsing is somewhat too permissive: julia> VERSION v"0.7.0-beta.275" julia> using Dates julia> tryparse(Date, "19800101", dateformat"yyyy-mm-dd") 19800101-01-01 Is this a bug or a feature? How can I get stricter validation?

It might not be as clear cut - what about 123 A.D.?

I would definitely call that a bug, you should probably file an issue.

The bigger issue to me is that it ignores the trailing -mm-dd part of the date format. That part of the data seems like it would be mandatory, not optional. The year could potentially be 19800101, although it might be sensible to only parse years as long as the given number of format digits.

Thanks for the discussion. Opened issue https://github.com/JuliaLang/julia/issues/28090

The DateFormat docs could probably be clearer here, but essentialy dateformat"y-m-d" ends up parsing the exact same dates as dateformat"yyyy-mm-dd"; the presence of a y or m just means, “parse the digits until another delimiter is encountered”. So the doc clarification should mention there’s current…

[image] quinnj: So while this might be surprising and maybe some enhancements need to be made, there’s not really any “bugs” here; this is definitely working as intended. Makes sense to me. I take it this is standard date parsing behavior and others do this as well? This definitely seems li…

[image] quinnj: there’s not really any “bugs” here; this is definitely working as intended Possibly, but at least the documentation should be improved then. ?DateFormat says yyyymmdd 19960101 Matches fixed-width year, month, and day which may lead the user to conclude that repeating char…

Yeah, there’s just a big difference parsing-wise between fixed-width and delimited. With fixed-width, obviously you’re expecting only a certain # of characters and more or less than what is specified is going to blow things up. With delimited though, what if you had a mix of date strings like ["201…

[image] quinnj: Another thing maybe we should consider is taking away the default values for month & day parts; that would mean you’d have to explicitly call Date(2018, 1, 1) instead of relying on defaults. That would have helped this situation because Date(19800101) would have thrown an error b…

[image] quinnj: how do you specify the “day” part for parsing? You either of a dateformat string like "yyyy-mm-dd" or "yyyy-m-d" , but you can’t really require one or two digits, because there might be both in a set of date strings to be parsed. I think what I get hung up on is that since the…

Stricter date parsing

General Usage

Liso July 14, 2018, 7:24am 20

This could be probably interesting here too:

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Stricter date parsing

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