earlier vs earliest

earlier and earliest both are adjectives.

Word	Noun	Adjective	Verb	Adverb
earlier	No	Yes	No	Yes
earliest	No	Yes	No	Yes

As adjectives, earlier and earliest are synonyms defined as:

earlier and earliest: (comparative and superlative of `early') more early than; most early

earlier (adjective)	earliest (adjective)
(comparative and superlative of `early') more early than; most early	(comparative and superlative of `early') more early than; most early

earlier (adverb)	earliest (adverb)
earlier in time; previously	with the least delay
comparatives of `soon' or `early'
before now