Season 10 EU:

What	When
Season 10 [EU] Signups Open	9th of June (20:00 CEST)
Season 10 [EU] Signups Close	14th of July (23:59 CEST)
Season 10 [EU] Seeding	15th of July
Season 10 [EU] Round 1 starts	29th of July
Season 10 [EU] Last round (10) starts	30th of September
Season 10 [EU] Last date to play regular season games	11th of October
Season 10 [EU] Draw Show	13th of October
Season 10 [EU] Playoff Group Stage starts	14th of October
Season 10 [EU] Playoffs end	3rd of November

Season 9 EU:

What	When
Season 9 [EU] Signups Open	3rd of February (19:00 CET)
Season 9 [EU] Signups Close	10th of March (23:59 CET)
Season 9 [EU] Seeding	11th of March
Season 9 [EU] Round 1 starts	25th of March
Season 9 [EU] Last round (10) starts	27th of May
Season 9 [EU] Last date to play regular season games	7th of June
Season 9 [EU] Draw Show	9th of June
Season 9 [EU] Playoff Group Stage starts	10th of June
Season 9 [EU] Playoffs end	30th of June

Season 2 NA:

What	When
Season 2 [NA] Signups Open	3rd of February (2:00 pm EST/11:00 am PST)
Season 2 [NA] Signups Close	24th of March (11:59 pm EST/8:59 am PST)
Season 2 [NA] Seeding	25th of March
Season 2 [NA] Round 1 starts	8th of April
Season 2 [NA] Last round (10) starts	10th of June
Season 2 [NA] Last date to play regular season games	21st of June
Season 2 [NA] Draw Show	23rd of June (7:00pm EST // 4:00pm PST )
Season 2 [NA] Playoff Group Stage starts	24th of June
Season 2 [NA] Playoffs end	14th of July

Season 3 NA:

What	When
Season 3 [NA] Signups Open	23rd of June - Announced on the Draw Show
Season 3 [NA] Signups Close	4th of August (11:59 pm EST/8:59 pm PST)
Season 3 [NA] Seeding	5th of August
Season 3 [NA] Round 1 starts	2nd of September
Season 3 [NA] Last round (10) starts	4th of November
Season 3 [NA] Last date to play regular season games	15th of November
Season 3 [NA] Draw Show	17th of November
Season 3 [NA] Playoff Group Stage starts	18th of November
Season 3 [NA] Playoffs end	15th of December