options(digits.secs=1) myformat.POSIXct <- function(x, digits=0) { x2 <- round(unclass(x), digits) attributes(x2) <- attributes(x) x <- as.POSIXlt(x2) x$sec <- round(x$sec, digits) format.POSIXlt(x, paste("%Y-%m-%d %H:%M:%OS",digits,sep="")) } t1 <- as.POSIXct('2011-10-11 07:49:36.3') format(t1) myformat.POSIXct(t1,1) t2 <- as.POSIXct('2011-10-11 23:59:59.999') format(t2) myformat.POSIXct(t2,0) myformat.POSIXct(t2,1)

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