时而
shí ér · HSK 6
from time to time
⏰ shí ér = time + and — and then time passes again
时 means time, 而 means and/but. Together they say and then time passes — things happen at scattered moments, occasionally, from time to time.
时 — sun 日 + temple/measure 寺
Originally a phono-semantic compound: 日 (sun) gives the meaning of time or season, while 寺 (shí) supplies the sound. Early forms used 之 as the phonetic before 寺 replaced it. The core sense 'season, time, hour' has stayed stable since ancient Chinese.
而 — pictograph of beard/whiskers hanging from chin
Originally a pictograph of a beard or facial hair hanging below the chin, visible clearly in oracle bone and bronze script forms. The beard meaning was lost early, and the character was borrowed phonetically to write the grammatical conjunction 'and/but/yet'. This connective use has been standard since classical Chinese.