= Stata Datetime Functions = Stata supports these '''datetime functions''' (i.e., numeric function designed for [[Stata/DataFormats#Date_and_Datetime_Formats|date and datetime formatted values]]) in the global scope. <> ---- == Functions Converting Integers == See [[Stata/NumericFunctions#Date_and_Time_Functions|Numeric Functions]]. ---- == Functions Converting a String == These functions convert a string into a numeric value that represents a date or time. '''Masks''' instruct how a date or time as represented in string data. A datetime format still must be separately applied to the numeric value. As an example, the mask of `"DMY"` can parse all of: * `"21nov2006"` * `"21 November 2006"` * `"21-11-2006"` * `"21112006"` Spaces are ignored in a mask; `"DMY"` is equivalent to `"D M Y"`. The mask `"DMY"` cannot parse a string with a two-digit year. A two-digit prefix can be applied to "Y" in the mask, such as "DM19Y". If a string has a two-digit year, such a mask will cause the year to be interpreted as being within the 1900s. If a string has a four-digit year, the mask will not mutate the value. ||'''Function Name'''||'''Meaning''' ||'''Output Format'''||'''Example''' || ||`clock(s,m)` ||Parse a datetime||`%tc` ||`clock(s,"YMDhms")` || ||`Clock(s,m)` ||Parse a datetime||`%tC` ||`Clock(s,"YMDhms")` || ||`date(s,m)` ||Parse a date ||`%td` ||`date(s,"MDY")` || ||`halfyearly(s,m)` ||Parse a halfyear||`%th` ||`halfyearly(s,"YH")`|| ||`monthly(s,m)` ||Parse a month ||`%tm` ||`monthly(s,"YM")` || ||`quarterly(s,m)` ||Parse a quarter ||`%tq` ||`quarterly(s,"YQ")` || ||`weekly(s,m)` ||Parse a week ||`%tw` ||`weekly(s,"YW")` || ||`yearly(s,m)` ||Parse a year ||`%ty` ||`yearly(s,"Y")` || ---- == Datetime Functions == These functions are intended for use on [[Stata/DataFormats#Date_and_Datetime_Formats|date and datetime formatted values]]. ||'''Function Name'''||'''Meaning''' ||'''Output Format'''|| ||`cofC(x)` ||Converts a `%tC`-formatted datetime ||`%tc` || ||`cofd(x)` ||Converts a date ||`%tc` || ||`Cofc(x)` ||Converts a `%tc`-formatted datetime ||`%tC` || ||`Cofd(x)` ||Converts a date ||`%tC` || ||`day(x)` ||Extracts the days component from a date ||n/a, in [1,31] || ||`dofc(x)` ||Converts a `%tc`-formatted datetime ||`%td` || ||`dofC(x)` ||Converts a `%tC`-formatted datetime ||`%td` || ||`dofh(x)` ||Converts a number of halfyears since the epoch ||`%td` || ||`dofm(x)` ||Converts a number of months since the epoch ||`%td` || ||`dofq(x)` ||Converts a number of quarters since the epoch ||`%td` || ||`dofw(x)` ||Converts a number of weeks since the epoch ||`%td` || ||`dofy(x)` ||Converts a number of years since the epoch ||`%td` || ||`dow(x)` ||Extracts the day of week from a date ||n/a, in [0,6] || ||`doy(x)` ||Extracts the day of year from a date ||n/a, in [1,366] || ||`halfyear(x)` ||Extracts the halfyear from a date ||n/a, in [1,2] || ||`hofd(x)` ||Converts a date ||`%th` || ||`hh(x)` ||Extracts the hours component from a `%tc`-formatted datetime ||n/a || ||`hhC(x)` ||Extracts the hours component from a `%tC`-formatted datetime ||n/a || ||`mm(x)` ||Extracts the minutes component from a `%tc`-formatted datetime||n/a || ||`mmC(x)` ||Extracts the minutes component from a `%tC`-formatted datetime||n/a || ||`month(x)` ||Extracts the months component from a date ||n/a, in [1,12] || ||`quarter(x)` ||Extracts the quarter from a date ||n/a, in [1,4] || ||`ss(x)` ||Extracts the seconds component from a `%tc`-formatted datetime||n/a || ||`ssC(x)` ||Extracts the seconds component from a `%tC`-formatted datetime||n/a || ||`week(x)` ||Extracts the week from a date ||n/a, in [1,52] || ||`year(x)` ||Extracts the years component from a date ||n/a || ||`mofd(x)` ||Converts a date ||`%tm` || ||`qofd(x)` ||Converts a date ||`%tq` || ||`wofd(x)` ||Converts a date ||`%tw` || ||`yofd(x)` ||Converts a date ||`%ty` || ---- == See also == [[https://www.stata.com/manuals/ddatetime.pdf|Stata datetimes]] ---- CategoryRicottone