How Do You Spell RETURNDAYS?
Pronunciation: [ɹɪtˈɜːnde͡ɪz] (IPA) 
The spelling of "returndays" can be explained using the International Phonetic Alphabet (IPA) as /rɪˈtɜːndeɪz/. The word is a combination of the verb "return" and the noun "days", indicating the number of days it takes to return something. The use of the letter "d" after the "n" is a result of the pluralization of the noun "days". The pronunciation of the final syllable, "-days", is emphasized with a voiced "z" sound. Overall, the spelling of "returndays" accurately represents its pronunciation.
