I can't seem to get a histogram of dates: tmt910% R --vanilla
R version 2.13.0 (2011-04-13) Copyright (C) 2011 The R Foundation for Statistical Computing ISBN 3-900051-07-0 ... > temp <- as.Date(1:200, origin="1970/01/01") > range(temp) [1] "1970-01-02" "1970-07-20" > hist(temp) Error in .Internal(inherits(x, what, which)) : 'x' is missing > traceback() 3: inherits(breaks, "Date") 2: hist.Date(temp) 1: hist(temp) Existence of hist.Date implies that this is intended to work. The MASS version fails in a different way. > library(MASS) > truehist(temp) Error in Ops.difftime(n, 2) : '%/%' not defined for "difftime" objects > sessionInfo() R version 2.13.0 (2011-04-13) Platform: x86_64-unknown-linux-gnu (64-bit) locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_US.UTF-8 LC_COLLATE=C [5] LC_MONETARY=C LC_MESSAGES=en_US.UTF-8 [7] LC_PAPER=en_US.UTF-8 LC_NAME=C [9] LC_ADDRESS=C LC_TELEPHONE=C [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] MASS_7.3-12 Terry Therneau ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.