Law 6

Solar Longitude on the Zodiac from to, not including[a] Lunar longitude correction
middle of Pisces-middle of Taurus [b] 315° 15°
middle of Taurus-beginning of Gemini 15° 30° 0°15′
beginning of Gemini-beginning of Leo 30° 90° 0°15′
beginning of Leo-middle of Virgo 90° 135° 0°15′
middle of Virgo-middle of Libra 135° 165°
middle of Libra-beginning of Sagittarius 165° 210° -0°15′
beginning of Sagittarius-beginning of Aquarius 210° 270° -0°30′
beginning of Aquarius-middle of Pisces 270° 315° -0°15′

[a] My understanding of the word usage in the original.

[b] See Chapter 11, Law 7 on the start of Jewish Zodiac. (TODO reference)

The value of mean [lunar longitude] after you add to it or subtract from it or leave it as it is - that is mean lunar longitude approximately a third of an hour after sunset on the date you are calculating it for. And this is what is called mean lunar longitude at observation time.