semestral vs semestrial

semestral and semestrial both are adjectives.

Word	Noun	Adjective	Verb	Adverb
semestral	No	Yes	No	No
semestrial	No	Yes	No	No

As adjectives, semestral and semestrial are synonyms defined as:

semestral and semestrial: occurring every six months or during every period of six months

semestral (adjective)	semestrial (adjective)
occurring every six months or during every period of six months	occurring every six months or during every period of six months