There are a number of standards for writing decimal numbers and dates. For decimal points, English-speaking countries tend to use a dot, but European countries use a comma. For dates, the Western European standard is “day, month, year”; the American standard is “month, day, year”; and the universal standard is “year, month, day”. This can cause confusion in interviews. Interviewers or respondents might see error messages if they use the wrong character as the decimal point, or they might misinterpret dates that are written using numbers only (for example, does “1/2/2017” mean “1 February” or “2 January”?).

The interview locale controls these aspects of an interview. It is closely related to the interview language and defaults to being the same as the interview language. When a new interview starts, the initial language and locale are set to match the respondent’s browser language or, if the script does not support that language, the questionnaire’s default language that was set during activation. Therefore, if the interview language is French, respondents must use a comma as the decimal point and should enter dates as dd/mm/yyyy; if the interview language is US-English, respondents must use a dot as the decimal point and should enter dates as mm/dd/yyyy. For more information about how to set the interview language, see Setting the interview language.

You can change the interview locale so that it differs from the interview language. You might do this if you want to enforce a particular method of entering or displaying numbers or dates regardless of the interview language. This would certainly make things easier for multilingual interviewers working on projects in areas with differing conventions for dates and decimal numbers. To set or change the locale, type:

where code is the locale ID in either hex or decimal format. For a list of locale IDs, see: