R Language
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- *apply family of functions (functionals)
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- Date-time classes (POSIXct and POSIXlt)
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- xgboost
R Language The Date class
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Remarks
Related topics
Jumbled notes
Date: Stores time as number of days since UNIX epoch on1970-01-01. with negative values for earlier dates.- It is represented as an integer (however, it is not enforced in the internal representation)
- They are always printed following the rules of the current Gregorian calendar, even though the calendar was not in use a long time ago.
- It doesn't keep track of timezones, so it should not be used to truncate the time out of
POSIXctorPOSIXltobjects. sys.Date()returns an object of classDate
More notes
- lubridate's
ymd,mdy, etc. are alternatives toas.Datethat also parse to Date class; see Parsing dates and datetimes from strings with lubridate. - data.table's experimental IDate class is derived from and is mostly interchangeable with Date, but is stored as integer instead of double.
