וַֽיְהִי֙ מִסְפַּ֣ר הַיָּמִ֔ים אֲשֶׁר֩ הָיָ֨ה דָוִ֥ד מֶ֛לֶךְ בְּחֶבְר֖וֹן עַל־בֵּ֣ית יְהוּדָ֑ה שֶׁ֥בַע שָׁנִ֖ים וְשִׁשָּׁ֥ה חֳדָשִֽׁים׃ (ס)
And the time that David was king in Hebron over the house of Judah was seven years and six months.
Read kabbalistic (mystical) interpretation of II Samuel 2:11: and classical mystical sources.