The Scriptures tell us that His/Their name is Yahweh Yahweh Elohim.  Exodus 33:19 – “And He said, I will cause all My goodness to pass before your face.  And I will call out the name of Yahweh  before your face ...”   Exodus 34:6 – “And Yahweh passed by before his face and called out:  Yahweh Yahweh Elohim.”  Deuteronomy 6:4 – “Hear, O Israel, Yahweh our Elohim is Yahweh echad.”  The word “echad” is plural, signifying more than one Yahweh.  Had only one Yahweh been meant, the word would have been “yachid” which is singular.
The first Yahweh is the Father, Yah Yahweh, whom we pray to as our Father, who art in heaven.  The second Yahweh is the Son, Yahshua Yahweh, also known as Yahshua Mashiyach, or Yahshua (Yah is salvation) the anointed/Jesus the Christ.  Elohim (Gods) is a uniplural noun (collective nouns are similar) which signifies unity in oneness.  This concept is the Jews "stone which causes offense".
Jesus said that only the heavenly Father knows when He (Jesus) will return.