Z is the 26th letter of the English Alphabet.
Z is the 7th letter of the Latin Alphabet.
In terms of the layout of the 7 days of the week it serves as way of linking Monday, Tuesday, Wednesday in the top line (corresponding to the Zodiac signs
Pisces (Monday) to Gemini (Wednesday) down to Sagitarrius (Thursday) and across to Virgo (Friday).
In Phoenician the Z is Zayin, means sword and is the 20th letter of Alphabet. This corresponds to the flaming sword of the Cabala long before Zorro borrowed the idea. Hence Z serves to close the Week and to close the Alphabet.
In Ogham Z = Straif = ST = Letter 14
The hieroglyph for Z is a Door Fastening.
Symbol 16:12
cf. Z History