TO READ: should_advise(...)

[garrettgman]

We should add a message to ymd( ) that appears depending on where ymd(
) is being used. The message reveals what format is being used.

ymd(..., advice = should_advise(...))

[garrettgman]

Do you remember what should_advise was advising people? I think it had something to do with where ymd() was called... it looks at the arguments and then either advises or doesn't advise based on what they are...

[hadley]

Two main uses for ymd etc.

• to create one or two dates for comparison: subset(df, date < ymd(20010405))
• to convert a whole lot of dates from character: df$date <- ymd(df$date)

In the first one don't want any feedback by default, but in the second you do.

[garrettgman]

The should advise function was unnecessary. We had parse date always executing
message("Using date format ", fmt, ".")
whenever ymd() was called. I changed it to
if (length(x) > 1) message("Using date format ", fmt, ".")
so it would only display the message if ymd() was evaluating more than one date at a time. This does the same thing that the should_advise() function would have

[hadley]

I'd make it > 2, but otherwise great :)

[garrettgman]

I changed it