Date1 <- as.Date(“2011-01-30”) Date2 <- as.Date(“2011-02-04”) sum(!weekdays(seq(Date1, Date2, “days”)) %in% c(“Saturday”, “Sunday”)) EDIT: And Zach said, let there be Vectorize 🙂 Dates1 <- as.Date(“2011-01-30”) + rep(0, 10) Dates2 <- as.Date(“2011-02-04”) + seq(0, 9) Nweekdays <- Vectorize(function(a, b) sum(!weekdays(seq(a, b, “days”)) %in% c(“Saturday”, “Sunday”))) Nweekdays(Dates1, Dates2)
I’d do it with lubridate and plyr, rounding dates down to the nearest month to make them easier to plot: library(lubridate) df <- data.frame( date = today() + days(1:300), x = runif(300) ) df$my <- floor_date(df$date, “month”) library(plyr) ddply(df, “my”, summarise, x = mean(x))
Astronomy versus Atomic clock By the original definitions the difference is that GMT (also officially known as Universal Time (UT), which may be confusing) is based on astronomical observations while UTC is based on atomic clocks. Later GMT has become to be used at least unofficially to refer to UTC, which blurs the distinction somewhat. … Read more
The same as you would in .NET: $DateStr = $Date.ToString(“yyyyMMdd”) Or: $DateStr=”{0:yyyyMMdd}” -f $Date
It’s in the python docs. import datetime datetime.datetime.combine(datetime.date(2011, 1, 1), datetime.time(10, 23)) returns datetime.datetime(2011, 1, 1, 10, 23)
In C#: // Define the input values. string[] input = { “2013-11-03 00:45:00”, “2013-11-03 01:00:00”, “2013-11-03 01:15:00”, “2013-11-03 01:30:00”, “2013-11-03 01:45:00”, “2013-11-03 01:00:00”, “2013-11-03 01:15:00”, “2013-11-03 01:30:00”, “2013-11-03 01:45:00”, “2013-11-03 02:00:00”, }; // Get the time zone the input is meant to be interpreted in. TimeZoneInfo tz = TimeZoneInfo.FindSystemTimeZoneById(“Eastern Standard Time”); // Create an array … Read more
Date/time values are being casted/parsed in a locale aware fashion Update: this is the default behavior with the CakePHP application template versions prior to 3.2.5. As of 3.2.5 locale parsing is not enabled by default anymore, which will make the date/time marshalling logic expect a default format of Y-m-d H:i:s instead. In the marshalling process, … Read more
Using Perl and hand-crafted regexes instead of facilities like strptime: #!/bin/perl -w while (<>) { # for date times that don’t use leading zeroes, use this regex instead: # (?:\d{1,2}/\d{1,2}/\d{4} )(\d{1,2})(?::\d\d:\d\d) (AM|PM) while (m%(?:\d\d/\d\d/\d{4} )(\d\d)(?::\d\d:\d\d) (AM|PM)%) { my $hh = $1; $hh -= 12 if ($2 eq ‘AM’ && $hh == 12); $hh += 12 … Read more
You can use an XmlAdapter to customize how a date type is written to XML. package com.example; import java.text.SimpleDateFormat; import java.util.Date; import javax.xml.bind.annotation.adapters.XmlAdapter; public class DateAdapter extends XmlAdapter<String, Date> { private final SimpleDateFormat dateFormat = new SimpleDateFormat(“yyyy-MM-dd HH:mm:ss”); @Override public String marshal(Date v) throws Exception { synchronized (dateFormat) { return dateFormat.format(v); } } @Override public … Read more