adverb
henceforth
hens-FORTH/ˌhensˈfɔːrθ/
From this time forward.
The arrows run henceforth from the highlighted present day across future calendars.

Etymology
The “from here” idea in hence combines with forth’s “onward.” Applied to time, the compound treats the present moment as a starting point and looks forward from it.
In context
no more shall the threat of sorcery be allowed to take the warriors of the astartes henceforth it is my will that no legion will maintain a librarious department
More examples
- The committee will henceforth meet on Mondays.
- Henceforth, please send invoices to our new address.
- This document is henceforth known as the agreement.
Similar words
- hereafter
- Also means from now on, but can suggest the afterlife.
- thereafter
- Begins at a previously mentioned time, not necessarily now.