A Genesis Day and the Age of the Earth: what does the Bible say?

In Gen the word'Day' refers to the daylight hours in contrast with the nighttime.
But later it goes on to use the word 'day' to refer to other units of time of varying length. In both the Hebrew and the Greek Scriptures, the word 'day' (Heb., yohm; Gr., heme′ra) is used in a literal and in a figurative or even symbolic sense.The Hebrews began their 'day' in the evening, after sunset, and ended it the next day at sunset. This shows that its not always based on daylight.Sometimes the word 'day' is used to indicate a measure of distance, as in the expressions 'a day’s journey' Nu 11:31The term 'day(s)' is also used with reference to a time period contemporaneous with a particular person, as for example, 'the days of Noah' and 'the days of Lot.' Lu 17:26-30 & Isa 1:1.But that strongest evidence for me that 'day' in genesis is not literally 24 hours long is that the account says that each day came to its completion with the words ... 'And there came to be evening and there came to be morning' a first, second, third, fourth, fifth, and sixth day. but the seventh day is not said to have come to its completion. Is that day still in progress??? Is God still resting from his creative works?Perhaps so because at Hebrews 4:1-10 the apostle Paul indicated that God’s rest day was still continuing in his generation, and that was more than 4,000 years after that seventh-day rest period began.