i have some cross clj-cljs code, which accesses a mysql db. If i select a date out using cljs (nodejs), it’s two hours off the clj version.

I use jdbc from clj, and mysql’s official npm from cljs

If I do SELECT @@system_time_zone;, it returns UTC from both

So what other options do I have for debugging?

which has the correct time?

my guess would be you are storing time without a timezone in mysql, and the timezone on you machine is 2 hours off from utc

That’s a good question 🙂 If I query the db via squirrelsql, it matches the clj version, but that doesn’t mean it’s true

Yes, it’s a TIMESTAMP, no timezone info. My machine is actually 1 hour off UTC (eg CET+1, no DST), so the difference puzzles me

I would check the date objects or whatever before you insert them into mysql

Well it’s not totally important for my use-case whether one or the other value is returned, the important part is that they should be equal. So I’m wondering if there’s something different in the way i connect to the db from clj and cljs.

I’m just wondering, if there are any other queries I can throw at the db from both clients, in order to debug

the timestamps are likely the same, but being turned in to date objects with whatever timezone

I doubt it is a db issue

well, you could call it a db issue, because you really should be storing a timezone

They’re js/Date and java.util.Date. None of those should have tz info, but they’re still different

I think it is, uh, a marshalling or serialization issue

they definitely do both have timezone info

Well, they’re UTC according to the docs I’ve read

clojure's prn prints Dates by converting them to utc, which could be deceptive here

grav: Date definitely does not default to utc, it defaults to whatever the system timezone is

if you prn out a Date object, and it shows a utc time, then call .getTime on that Date object, the getTime will be in the timezone of the Date object, not utc

Okay, I’ll try that

(println (str date-object)) will print out the timezoned date

oh, whoops, actually getTime is always gmt

Well, it seems the cljs instance of the date is off. Which puzzles me since it’s the official mysql npm

Ah, needed to supply :timezone “utc” to my connection map. Apparently SELECT @@system_time_zone; wasn’t telling the truth

http://stackoverflow.com/questions/23571110/nodejs-responded-mysql-timezone-is-different-when-i-fetch-directly-from-mysql

Funny, also UTC+2. Seems like a bug.

@hiredman anyway, thanks for the pointers 🙂