time: uppercase day/month names are not recognized in format strings

[bupjae]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go 1.7

What operating system and processor architecture are you using (go env)?

play.golang.org

What did you do?

https://play.golang.org/p/ORGoq1knm0

What did you expect to see?

Tue Nov 10 2009
TUE NOV 10 2009

What did you see instead?

Tue Nov 10 2009
MON JAN 10 2009

While "Mon" and "Jan" are parsed as placeholder, I was surprised "MON" and "JAN" are not parsed.

The documentation https://golang.org/pkg/time/ is not sufficient to determine format string specification without examining source code https://golang.org/src/time/format.go .

[cznic]

The documentation https://golang.org/pkg/time/ is not sufficient to determine format string specification without examining source code https://golang.org/src/time/format.go .

Let me disagree please. From the docs:

The reference time used in the layouts is the specific time:

Mon Jan 2 15:04:05 MST 2006

which is Unix time 1136239445. Since MST is GMT-0700, the reference time can be thought of as

01/02 03:04:05PM '06 -0700

To define your own format, write down what the reference time would look like formatted your way; see the values of constants like ANSIC, StampMicro or Kitchen for examples.

The format string in your example obviously is not 'what the reference time would look like formatted your way' b/c it uses MON instead of Mon etc, but nowhere is such thing documented to be allowed.

[quentinmit]

@cznic This request seems reasonable to me; they're saying that "MON" is how they wanted the day to be formatted. We ought to either document the allowed symbols or support upper/title/lower case.

[gopherbot]

CL https://golang.org/cl/32636 mentions this issue.