PAT *š́ǝ- in compounds: Abkh. á-š́ǝ-bž́, Abaz. š́ǝ-bž́a-n 'noon' ( < *š́ǝ-bǝža, see *bǝža 'half'); Abkh. á-š́ǝ-ž́ 'morning', Abaz. š́až́ǝ 'early in the morning'. In the AK word (*jǝ-ʎá-sǝ) jǝ- is a pronominal prefix; meaning of the final component (-sǝ) is not quite clear (cf. *-sa in *pá-sa 'early'?). Shagirov's (1, 185) hypothesis of a Turk. origin seems, anyway, very improbable.
The original meaning of the root is not clear ('time' in general?). Note that the corresponding root in Avaro-Andian languages has the same range of meanings.