src/sap.ui.core/src/sap/ui/core/Configuration.js
function(sFormatLocale) {
			var oFormatLocale = convertToLocaleOrNull(sFormatLocale),
				mChanges;

			check(sFormatLocale == null || typeof sFormatLocale === "string" && oFormatLocale, "sFormatLocale must be a BCP47 language tag or Java Locale id or null");

			if ( toLanguageTag(oFormatLocale) !== toLanguageTag(this.formatLocale) ) {
				this.formatLocale = oFormatLocale;
				mChanges = this._collect();
				mChanges.formatLocale = toLanguageTag(oFormatLocale);
				this._endCollect();
			}
			return this;
		}
function(sFormatLocale) {
			var oFormatLocale = convertToLocaleOrNull(sFormatLocale),
				mChanges;

			check(sFormatLocale == null || typeof sFormatLocale === "string" && oFormatLocale, "sFormatLocale must be a BCP47 language tag or Java Locale id or null");

			if ( toLanguageTag(oFormatLocale) !== toLanguageTag(this.formatLocale) ) {
				this.formatLocale = oFormatLocale;
				mChanges = this._collect();
				mChanges.formatLocale = toLanguageTag(oFormatLocale);
				this._endCollect();
			}
			return this;
		}
function ( sFormatLocale ) { var oFormatLocale = convertToLocaleOrNull ( sFormatLocale ) , mChanges ; check ( sFormatLocale == null || typeof sFormatLocale === "string" && oFormatLocale , "sFormatLocale must be a BCP47 language tag or Java Locale id or null" ) ; if ( toLanguageTag ( oFormatLocale ) !== toLanguageTag ( this . formatLocale ) ) { this . formatLocale = oFormatLocale ; mChanges = this . _collect ( ) ; mChanges . formatLocale = toLanguageTag ( oFormatLocale ) ; this . _endCollect ( ) ; } return this ; }
Sets a new format locale to be used from now on for retrieving locale
specific formatters. Modifying this setting does not have an impact on
the retrieval of translated texts!

Can either be set to a concrete value (a BCP47 or Java locale compliant
language tag) or to <code>null</code>. When set to <code>null</code> (default
value) then locale specific formatters are retrieved for the current language.

After changing the format locale, the framework tries to update localization
specific parts of the UI. See the documentation of {@link #setLanguage} for
details and restrictions.

<b>Note</b>: When a format locale is set, it has higher priority than a number,
date or time format defined with a call to <code>setLegacyNumberFormat</code>,
<code>setLegacyDateFormat</code> or <code>setLegacyTimeFormat</code>.

<b>Note</b>: See documentation of {@link #setLanguage} for restrictions.

@param {string|null} sFormatLocale the new format locale as a BCP47 compliant language tag;
case doesn't matter and underscores can be used instead of dashes to separate
components (compatibility with Java Locale IDs)
@return {sap.ui.core.Configuration} <code>this</code> to allow method chaining
@public
@throws {Error} When <code>sFormatLocale</code> is given, but is not a valid BCP47 language
tag or Java locale identifier
Sets a new format locale to be used from now on for retrieving locale specific formatters . Modifying this setting does not have an impact on the retrieval of translated texts!