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August 17, 2013 19:58
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Date Formats in R
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# importing dates: | |
dates <- c("05/27/84", "07/07/05") | |
betterDates <- as.Date(dates, | |
format = "%m/%d/%y") # here you put the format your dates are currently in | |
# it will output the ISO standard dates (%Y-%m-%d) | |
# or: | |
dates <- c("May 27 1984", "July 7 2005") | |
betterDates <- as.Date(dates, | |
format = "%B %d %Y") | |
betterDates | |
# from Windows Excel: | |
dates <- c(30829, 38540) | |
betterDates <- as.Date(dates, | |
origin = "1899-12-30") | |
betterDates | |
# from Mac Excel: | |
dates <- c(29367, 37078) | |
betterDates <- as.Date(dates, | |
origin = "1904-01-01") | |
betterDates | |
# using dates: | |
format(betterDates, | |
"%a %b %d") | |
mean(betterDates) | |
max(betterDates) | |
min(betterDates) | |
# fixing centuries: | |
dates <- c("05/27/84", "07/07/05", "08/17/20") | |
betterDates <- as.Date(dates, "%m/%d/%y") | |
correctCentury <- as.Date(ifelse(betterDates > Sys.Date(), | |
format(betterDates, "19%y-%m-%d"), | |
format(betterDates))) | |
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Out of all the different date functions available ( i.e. a,b,d,j,w,u etc), i can't use any combination of them to specify format? they necessarily need to be a system recognized combination?