Final Clue: Luke 23:54-56
Luke 23:54 That day was the Preparation, and the Sabbath drew near.
55 And the women who had come with Him from Galilee followed after, and they observed the tomb and how His body was laid.
56 Then they returned and prepared spices and fragrant oils. And they rested on the Sabbath according to the commandment.
By the way, the Biblical day starts as soon as it gets dark in the evening when the sun has completely set, right after twilight as shown in Nehemiah 13:19:
Neh 13:19 So it was, at the gates of Jerusalem, as it began to be dark before the Sabbath, that I commanded the gates to be shut, and charged that they must not be opened till after the Sabbath. Then I posted some of my servants at the gates, so that no burdens would be brought in on the Sabbath day.
Note that the phrase “as it began to be dark” is what's called twilight nowadays. And this twilight period is still before the Sabbath or the ending of Biblical Friday. Sabbath or any Biblical day for that matter starts at dark when the sun has completely set.
Jesus died in the mid-afternoon of Nissan 14, same time the symbolic Passover lamb were killed since the time of Moses. See the article "When was the passover sacrificial lamb slain?"
Passover day was called Preparation day because the Israelites had to get rid of leavening from their houses and surroundings in preparation for the Days of Unleavened Bread. Also, in the mid-afternoon the Passover sacrificial lamb were killed, to be eaten in the ensuing evening
That evening when the sun has completely set was the start of the First Day of Unleavened Bread. This is a commanded Holy Day, an annual Sabbath.
So the women had to wait till after this annual Sabbath before they could buy and prepare the spices. Work, buying and selling are forbidden both on weekly and annual Sabbaths. So on Friday they were able to buy and prepare the spices and fragrant oils. Then they rested on the weekly Sabbath afterwards.
To recap the timeline, Jesus died on Wednesday mid-afternoon. By the time He was taken down from the stake (staurus) and then prepared for burial, it was close to evening, the start of the annual Sabbath, the First Day of Unleavened Bread which fell on Thursday that week.
On Friday, the women bought and prepared the spices and fragrant oils. Then they rested on the weekly Sabbath. As the story goes, they brought the prepared spices and fragrant oils to the tomb early morning on Sunday.
Astronomical Evidence
The Biblical month starts at the dark phase of the moon, as it says in Psalms 81:3
Ps 81:3 Blow the ram's horn in the new moon, on the covered moon, on our feast day. (Hebraic Roots Bible)
The Hebrew word for “covered moon” is kesah which means "covered" and hence the moon is not visible, the dark phase. That is the Biblical new moon, the start of Biblical month.
So that year in 30 AD, Nissan 1 started in the evening of the Roman day March 22 when the moon was in the dark phase in Jerusalem. See the depiction of the moon phase that evening from U.S. Naval Observatory data:
New Moon (Dark Phase) of the Moon on March 22, 30 AD 6 PM
Jerusalem (Latitude 31.46 N, Longitude 35.14 E)
Nissan 1 of 30 AD is equivalent to March 23, 30 AD of the Roman calendar. Counting forward, Nissan 14 of 30 AD is equivalent to April 5, 30 AD which fell on a Wednesday. This is consistent with the Gospel account timeline as mentioned above. No other year near 30 AD did Nissan 14 or Passover Day fall on a Wednesday.
In conclusion, our Saviour paid for the sin of mankind by giving up His life in the afternoon of April 5, 30 AD.