Date

Create

Action	Code	Details
From ymd	ISOdate(year, month, day) |> as.Date()
From ymd	lubridate::make_date(year, month, day)
Current date	Sys.Date()
Current date	lubridate::today() |> as.Date()
Current date in UTC timezone	lubridate::today(tzone = 'UTC') |> as.Date()
Unix epoch	as.Date(0)
From total days since Unix epoch	as.Date(n)
From total days since reference date	as.Date(n, origin = ref_date)
Date from YYYY-MM-DD string	as.Date(x)
Date from Y-m-d ordered string	lubridate::ymd(x)
Date from DD-MMM-YYYY string	as.Date(x, '%Y-%m-%d')
Date from d-m-Y ordered string	lubridate::dmy(x)

Vector of dates

Action	Code	Details
Vector of length n filled with date d	rep(d, n)
Sequence (vector) of n consecutive dates, starting from d	seq(d, length.out = n, by = 'day')
Sequence of n consecutive dates, starting from d	seq(d, length.out = n, by = 'day')
Sequence (vector) of consecutive dates between dates d and d2	seq(d, d2, by = 'day')
Sequence of n dates, starting from d with weekly increments	seq(d, length.out = n, by = 'week')
Sequence of n dates counting down from date d with weekly decrements	seq(d, length.out = n, by = '-1 week')
Sequence of n dates, starting from d with w-week increments	seq(d, length.out = n, by = 'w week')
Sequence of dates between d and d2 with weekly increment	seq(d, d2, by = 'week')
Sequence of n dates, starting from d with yearly increments	seq(d, length.out = n, by = 'year')

Constants

Action	Code	Details
NA	lubridate::NA_Date_

Test

Action	Code	Details
Is date	lubridate::is.Date(x)
Same date	x == y
Happens before y	x < y
Happens after y	x > y

Extract

Action	Code	Details
Days from Unix epoch	as.integer(x)
Seconds from Unix epoch (timestamp)	as.POSIXct(x) |> as.integer()
Year	lubridate::year(x)
Month	lubridate::month(x)
Day	lubridate::day(x)
Week number (1-53)	lubridate::week(x)
ISO week number (1-52)	lubridate::isoweek(x)
Weekday number	lubridate::wday(x, week_start = 1)	Mon=1, Sun=7

Update

Action	Code	Details
Change to first day of year	lubridate::yday(x) = 1
Change to first day of month	lubridate::day(x) = 1
Change year to y	lubridate::year(x) = y

Derive

Action	Code	Details
Change to first day of year	trunc(x, 'year')
Change to first day of month	trunc(d, 'month')
Shift forward by n days	x + n

Convert

Action	Code	Details
To datetime at midnight (00:00:00) in UTC	as.POSIXct(x)
To POSIXct at midnight (00:00:00) in UTC	as.POSIXct(x)
To POSIXlt at midnight (00:00:00) in UTC	as.POSIXlt(x)

Format

Action	Code	Details
Format as ISO date (yyyy-mm-dd)	format(x)
Format as dd-mm-yyyy	format(d, '%d-%m-%Y')
Format in system locale	format(x, '%a %b %d')