The upfronts and fall launches start with both the U.S. and French Canadian networks from mid-to-late May followed by the English Canadian networks in early June.
Here is a listing of the dates when both the U.S. and Canadian networks will be announcing their 2018/19 lineups.
Generally, the announcements are made via press release earlier in the day of the scheduled upfronts before the live presentations are made to advertisers in the afternoon.
U.S. NETWORKS
Monday May 14 - NBC (morning, press release issued on Sunday May 13) and FOX (afternoon)
Tuesday May 15 - ABC (afternoon)
Wednesday May 16 - CBS (afternoon)
Thursday May 17 - The CW (morning)
CANADIAN NETWORKS
Thursday May 10 - Québecor (TVA) - Montréal
May 30 - Toronto
June 13 - Québec City
Tuesday May 15 - Groupe V Média (V Télé) - Montréal
May 23 - Toronto
May 30 - Québec City
Thursday May 17 - Télé-Québec - Montréal
May 23 - Québec City
Wednesday May 23 - Serdy Média - Montréal (Longueuil)
Tuesday May 29 - CBC / Radio-Canada - Toronto (National Upfronts)
May 28-31 - Montréal
June 19 - Québec City
Tuesday May 29 - TV5 & Unis TV - Montréal
June 14 - Toronto
Wednesday May 30 - indieNET Fall 2018 Launch (CHCH, yesTV, NTV, CHEK) - Toronto
Tuesday May 31 - Télé-Québec and Groupe Serdy - Toronto (joint launch)
Tuesday June 5 - Rogers Media (City) - Toronto (National Upfronts)
June 12 - Calgary
June 13 - Edmonton
June 14 - Vancouver
Wednesday June 6 - Corus Media (Global) - Toronto (National Upfronts)
June 13 - Montréal
Thursday June 7 - Bell Media (CTV) - Toronto (National Upfronts)
June 12 - Edmonton
Tuesday June 26 - Blue Ant Media + Blue Ant Plus presents The Business of Storytelling - Toronto
Source: https://thinktv.ca/post/upfronts-2018/