Two days of darkness before chopping is supposed to boost resin, and it gets repeated for sativas because people are desperate to squeeze something extra from a four month grow. I have tried it on the same Haze cut side by side and could not tell the difference in frost, smell or effect. A small controlled comparison written up on https://hazesativaseeds.com came to the same conclusion, with photos under the same light. Harvest when the trichomes say so, the extra 48 hours of dark is just delay.
