The Romans had eight day “weeks,” with the days indicated by letter names (A-H). Each “ninth” day (inclusive counting) was a market day.
The names of our seven day week are post-classical and were based on the names of astrological bodies (with the planets named for divinities). For more on the Latin names, see Isidore. Our English names are based on these Latin names, with the genitive (possessive form: -es) of equivalent Celtic and/or Norse deity names substituted.
The names of our seven day week are post-classical and were based on the names of astrological bodies (with the planets named for divinities). For more on the Latin names, see Isidore. Our English names are based on these Latin names, with the genitive (possessive form: -es) of equivalent Celtic and/or Norse deity names substituted.
| Latin | French | Spanish | Italian | Rumanian | English Names |
| Dies solis/ dies dominicus (sun/ Lord’s day) | dimanche | domingo | domenica | Duminica | Sun-day |
| lunae dies (moon) | lundi | lunes | lunedi | Luni | Monday (moon) |
| Martis dies (Mars) | mardi | martes | martedi | Marti | Tuesday (Tiw: Teutonic deity) |
| Mercurii dies (Mercury) | mercredi | miércoles | mercoledi | Miercuri | Wednesday (Woden= Norse Odin) |
| Iovis dies (Iuppiter, Iovis) | jeudi | jueves | giovedi | Joi | Thursday (genitive of Thunor “Thunder [god]” cf. Thor) |
| Veneris dies (Venus) | vendredi | viernes | venerdi | Vineri | Friday (Norse Frigg, wife of Odin) |
| Saturni dies (Saturn) or sabbata (Sabbath,) | samedi | sábado | sabato | Sâmbata | Saturday (Saturn) |
Portuguese uses numbers for most of the days: segunda-feira (Monday), terça-feira, quarta-feira, quinta-feira, sexta-feira, sábado, domingo.