Was the formatting syntax of simpledateformat invented by Java?

Is the syntax of the date time format string defined by the simpledateformat class of Java (such as "EEE, mmm D", "YY", etc.). Is it the original Java invention, or is it based on some other syntax definitions, such as ICU's or cldr's?

Does anyone know how to compare the simpledateformat syntax with other definitions?

Solution

Java. Java introduced in JDK 1.1 text.*, ICU based:

ICU has simpledateformat, indicating that its symbol is based on the algorithm and pattern letter defined by "uts#35 Unicode locale data markup language (ldml)", which can be found here

Interestingly, the date pattern chapter introduced the Unicode technical report of revision for 3 years from October 27, 2004 #35 So could ICU be the original author?