Numbers and Dates

Word breakers must use a common format for representing numbers, times, and dates to facilitate consistent querying.

Numbers

When you create a word breaker, it is recommended that the word breaker normalize numbers to a canonical representation by using the pattern "NNddDcc," where "NN" is the literal sequence "NN," dd is the integer portion of the number, "D" is the literal "D," and cc is the fractional portion of the number. Word breakers do not restrict the number of digits for either the integer or the fraction portion of the number. It is recommended that word breakers recognize numerical patterns that are delimited by both periods (.) and commas (,). For example, Indexing Service represents both "1,000.2" and "1.000,2" as "NN1000D2."

Choose one format for both word breaker and stemmer. Single-byte Arabic numerals are normalized such that a query containing any of these forms matches documents with the other forms.

Times

When you create a word breaker, it is recommended that the word breaker present all times as a 24-hour representation that consists of a literal prefix "TT" followed by the time specification "TThhmmss," where hh is the hours, mm is the minutes, and ss is the seconds. Indexing Service does not match additional units of time, such as milliseconds. Parsing A.M. and P.M. patterns is optional.

Dates

When you create a word breaker, it is recommended that the word breaker generate dates in the canonical format of "DDyyyymmdd," where "DD" is the literal "DD," yyyy is the years, mm is the months, and dd is the days. It is also recommended that word breakers store two-digit years in both twentieth-century and twenty-first-century formats. For example, word breakers represent "2.2.99" as "DD19990202" and "DD20990202." At query time, Indexing Service derives the date by using Windows application programming interfaces (APIs) to determine the crossover date for the server to display the correct format, 19XX or 20XX.