Convert year.week to date

Question

I have times in the format YYYY.week:

x <- c("2016.49", "2016.50", "2016.51", "2016.52", "2017.01", "2017.02", "2017.03", "2017.04", "2017.05")

Is there a way to create the convert it to date variables like this (date is not true, but that's the desired format):

as.Date(x[1])
"2017-02-01"

score 2 · Answer 1 · answered Jan 27 '20 at 09:27

2

One lubridate option could be:

ymd(paste0(substr(x, 1, 4), "-01", "-01"))+weeks(as.numeric(substr(x, nchar(x)-1, nchar(x)))-1)

 [1] "2016-12-02" "2016-12-09" "2016-12-16" "2016-12-23" "2017-01-01"

Sample data:

x <- c("2016.49", "2016.50", "2016.51", "2016.52", "2017.01")

answered Jan 27 '20 at 09:27

tmfmnk

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thank you very much, clever solution, but the other one is a bit easier :) – Data Mastery Jan 27 '20 at 09:33

Aron Strandberg · Accepted Answer · 2020-01-28T09:13:39.343

2

If you append a weekday then as.Date will work:

x <- c("2016.49", "2016.50", "2016.51")

as.Date(paste0(x, ".1"), "%Y.%U.%u")

[1] "2016-12-05" "2016-12-12" "2016-12-19"

edited Jan 28 '20 at 09:13

answered Jan 27 '20 at 09:28

Aron Strandberg

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score 2 · Answer 3 · answered Jan 27 '20 at 10:07

2

One more lubridate option

parse_date_time(paste0(x,'.Mon'),'Y/W/a')
[1] "2016-12-05 UTC" "2016-12-12 UTC" "2016-12-19 UTC" "2016-12-26 UTC" "2017-01-02 UTC"

answered Jan 27 '20 at 10:07

Yuriy Barvinchenko

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Convert year.week to date

3 Answers3