No leading zeros for months R

Question

format() in R does not have an obvious option to display the month without leading 0 (and the same with the year). Is there another way to get this result? The solution should allow the user to flexibly choose whether 0s are to be omitted only for the day or the month or the year or for any combination.

in: as.Date("2005-09-02")

out: 2/9/5

or 0 only removed for month:

out: 2/9/05

Rich Scriven · Answer 1 · 2014-12-20T22:13:59.560

8

You can try this.

x <- as.Date(c("2005-09-02", "2005-10-20", "2010-10-20"))

gsub("0(\\d)", "\\1", format(x, "%d/%m/%y"))
# [1] "2/9/5"    "20/10/5"  "20/10/10"

But keep in mind that doing this on a vector of dates from different centuries will make things a bit confusing when you go back to look at them later.

edited Dec 20 '14 at 22:13

answered Dec 20 '14 at 21:15

Rich Scriven

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What about 2005-10-20 ? – G. Grothendieck Dec 20 '14 at 22:04
@G.Grothendieck - thanks I think my edit should take care of that – Rich Scriven Dec 20 '14 at 22:14
Ok, works if all leading 0s are to be stripped. But what, if the year should keep its zero and month not: as in out: # [1] "2/9/05" "20/10/05" "20/10/10" ?? – Andri Signorell Dec 21 '14 at 01:47
@AndriSignorell - that's not what your question asks for. It asks how to strip leading zeros from everything including the year – Rich Scriven Dec 21 '14 at 01:53
@Richard: The example was unclear, sorry. I need a solution to flexibly remove leading 0s either on m or on y or on both. – Andri Signorell Dec 21 '14 at 02:08

score 2 · Accepted Answer · answered Dec 20 '14 at 22:14

2

A solution with sub:

x <- as.Date("2005-09-02")
sub("..0?(.+)-0?(.+)-0?(.+)", "\\3/\\2/\\1", x)
# [1] "2/9/5"

answered Dec 20 '14 at 22:14

Sven Hohenstein

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Thanks for your solution, this seems promising. How would I access a group >9? \\10 does not work... – Andri Signorell Dec 21 '14 at 02:57

score -4 · Answer 3 · answered Dec 20 '14 at 21:13

-4

You can do this but you need to set it as a character because that format is not an actual date format.

X = "2005-09-02"
date = paste(substr(X,10,10),"/",substr(X,7,7),"/",substr(X,4,4),sep='')

answered Dec 20 '14 at 21:13

user2600629

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This is incorrect. The goal isn't to print one digit per field, but to suppress leading `0`'s. – Matthew Lundberg Dec 21 '14 at 03:00

No leading zeros for months R

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