the week Thursday bears his name (modern English Thursday derives from Old English , 'Þunor's day'), and names stemming from the pagan period containing his own continue to be used today, particularly in Scandinavia. Thor has inspired numerous works of art and references to Thor appear in modern popular culture. Like other Germanic deities, veneration of Thor is revived in the modern period in Heathenry. Name The Old Norse theonym (older poetic ) goes back to an earlier Proto-Norse form reconstructed as . It is a cognate (linguistic sibling of the same origin) of the medieval Germanic forms (Old High German), (Old English), (Old Frisian), and (Old Saxon). They descend from the Proto-Germanic reconstructed theonym ('Thunder'), which is identical to the name of the ancient Celtic god Taranus (by metathesis–switch of sounds–of an earlier , attested in the dative tanaro and the Gaulish river name Tanarus), and further related to the Latin epithet Tonans (attached to Jupiter), via the common Proto-Indo-European root for 'thunder' . According to scholar Peter Jackson, those theonyms may have emerged as the result of the fossilization of an original epithet (or epiclesis, i.e. invocational name) of the Proto-Indo-European thunder-god , since the Vedic weather-god Parjanya is also called ('Thunderer'). The perfect match between the thunder-gods *Tonaros and *Þun(a)raz, which both go back to a common form *ton(a)ros ~ *tṇros, is notable in the context of early Celtic–Germanic linguistic contacts, especially when added to other inherited terms with thunder attributes, such as *Meldunjaz–*meldo- (from *meldh- 'lightning, hammer', i.e. ' weapon) and *Fergunja–*Fercunyā (from 'wooded mountains', i.e. *Perkwunos' realm). The English weekday name Thursday comes from Old English Þunresdæg, meaning 'day of Þunor'. It is cognate with Old Norse Þórsdagr and with Old High German Donarestag. All of these terms derive from the Late Proto-Germanic weekday *Þonaresdag ('Day of '), a calque of Latin ('Day of Jove'; cf. modern Italian , French , Spanish ). By employing a practice known as during the Roman period, ancient Germanic peoples adopted the Latin weekly calendar and replaced the names of Roman gods with their own. Beginning in the Viking Age, personal names containing the theonym are recorded with great frequency, whereas no examples are known prior to this period. -based names may have flourished during the Viking Age as a defiant response to attempts at Christianization, similar to the wide scale Viking Age practice of wearing Thor's hammer pendants.