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I have data in YYMMDDHH format but am trying to get the weekday so I need to go to a date format but can't figure it out.

Here's a dput of the relevant data:

structure(list(id = c(7927751403363142656, 18236986451472797696, 
5654946373641778176, 14195690822403907584, 1693303484298446848, 
1.1362181921561e+19, 11694645532962195456, 1221431312630614784, 
1987127670789791488, 379819848497418688), hour = c(14102118L, 
14102217L, 14102812L, 14102912L, 14102820L, 14102401L, 14102117L, 
14102312L, 14102301L, 14102414L)), .Names = c("id", "hour"), row.names = c(3620479L, 
8510796L, 29632625L, 34450879L, 31874113L, 13420799L, 3332671L, 
11543560L, 9602012L, 15574701L), class = "data.frame")

When I use:

dat2$dow <- as.Date(substr(as.character(dat2$hour), 1,6), format = '%Y%m%d')

I just get NA's. Any suggestions?

screechOwl
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1 Answers1

6

"%Y" is for 4-digit years; "%y" is for 2-digit years. And you don't need to use substr. as.Date will ignore anything after the end of the specified format.

dat2$dow <- as.Date(as.character(dat2$hour), format='%y%m%d')
Joshua Ulrich
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