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Flowering time-SA

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From my calcs the first 12hour day is


26 Feb.  rise 06.58am  set 07:58pm gives a sun length of 12 hours 59 mins


and the first time we hit exactly 12 hours of sunlight will be


24 March  rise 07.21am  set 07:22pm


this is based on Adelaide GPS


but I find mine flower outside when they want to :) but should be somewhere around there.


Hope this helps

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The length of day changes with latitude. So plants grown outside in nth QLD will begin to flower earlier than the same strain grown in TAS.


I'm slightly further south than Adelaide and here early strains begin flowering mid Jan (eg. early pearl, early skunk, non autoflowering individuals of ruderalis skunk). Indica dominant strains begin flowering during the final week of January (eg. sensi skunk, skunk#1, hindu kush), sativas between 2 weeks and a month later (no eg's because I haven't grown any commercial sativas outside).


And just a note... when you calculate the day length it isn't enough to count from sunrise to sunset. You need to take account of the civil twilight ie; the time period between first light and sunrise and between sunset and last light. Civil twilight also varies with latitude, Just like the overall day length, the closer you get to the equator the shorter the civil twilight period.

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Yes sorry was a BIT wasted at the time of post and didn't want to get too technical. The observed times will differ by approx. four minutes for every degree of longitude from Adelaide (add four minute for Whyalla and 20 mins for Ceduna or subtract 8 mins for Mount Gambier).


According to the act (Proof of Sunrise and Sunset Act) (yes its a real thing)


The times are the instant the upper edge of the sun appears to lie on the horizon for an observer at sea level. An allowance of 34' has to be made for refraction and a further allowance of 16' made for the semi-diameter of the sun. The suns parallax ( a max of 0'09" ) is to be ignored as it is far smaller than the adopted uncertainty in the value for refraction.


But hey its just an estimate.....




Edited by Knarfman
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