古愛爾蘭語
Many calendrical and time-keeping terms used in the medieval and modern Celtic languages were borrowed from Latin and reflect the influence of Roman culture and Christianity on the Insular Celts. The words borrowed include the month names "Januarius" (Old Irish ', Irish "Eanáir", Welsh '), "Februarius" (Old Irish ', Irish "Feabhra", Welsh '), "Martius" (Old Irish ', Welsh '), "Aprilius" (Old Irish ', Irish "Aibreán", Welsh '), "Maius" (Welsh '), "Augustus" (Old Irish ', Welsh '); the names for the days of the week, "Solis", "Lunae", "Martis", "Mercurii", "Jovis", "Veneris", "Saturni"; the terms "septimana" "week" (Old Irish ', Breton ', Cornish '), "kalendae" "first day of the month" (Old Irish ', Welsh ', Breton '), "tempore" "time" (Welsh '), "matutina" "morning" (Cornish ', Irish "maidin"), "vespera" "evening", "nona" "noon" (Welsh ', Irish "nóin"), and "ôra" "hour" (Welsh ', Breton ', Irish "uair").