This is what I managed to cobble together. Should anything be wrong or missing, please let me know and I will update. I will also do so, to the best of my abilities, as time goes by.
National Selection / National Final / Internal Selection / Talent Show / ESC events
January
DENMARK reveals songs
UKRAINE reveals songs
11 January
LITHUANIA First Heat
NORWAY Semifinal One (Southern)
15 January
PORTUGAL reveals songs
18 January
LITHUANIA Second Heat NORWAY Semifinal Two (Eastern) 
LATVIA reveals songs
ICELAND reveals songs
20 January
CZECH REPUBLIC reveals songs
21 January
FINLAND reveals songs
25 January
LITHUANIA Third Heat NORWAY Semifinal Three (Central)
27 January
BELARUS Live Auditions
28 January
ESC Semifinal allocation draw
30 January
SPAIN reveals song (Blas Cantó)
1 February
LITHUANIA Semifinal One NORWAY Semifinal Four (Western) 
SWEDEN Semifinal One (Linköping)
3 February
CZECH REPUBLIC reveals winning artist and song
4 February
ITALY – Sanremo First Night
ISRAEL Next Star for Eurovision Grand Final - artist
5 February
ITALY – Sanremo Second Night
6 February
ITALY – Sanremo Third Night 
SERBIA reveals songs
7 February
ITALY – Sanremo Fourth Night
8 February
AUSTRALIA – National Final ITALY – Sanremo Fifth and Final Night LATVIA National Final ICELAND Semifinal One LITHUANIA Semifinal Two NORWAY Semifinal Five (Northern) SWEDEN Semifinal Two (Gothenburg) UKRAINE Semifinal One 
MALTA X Factor Grand Final - artist
11 February
ROMANIA reveals artist
13 February
ESTONIA Semifinal One
15 February
LITHUANIA National Final NORWAY National Final 
ARMENIA – National Final ESTONIA Semifinal Two ICELAND Semifinal Two SWEDEN Semifinal Three (Luleå) UKRAINE Semifinal Two
16 February
FRANCE reveals song (Tom Leeb)
17 February
BELGIUM reveals song (Hooverphonic)
21 February
ROMANIA reveals songs (Roxen)
22 February
SLOVENIA National Final UKRAINE National Final PORTUGAL Semifinal One SWEDEN Semifinal Four (Malmö)
23 February
POLAND A Chance for Success Grand Final – artist and song
27 February
GERMANY reveals artist and song
UNITED KINGDOM reveals artist and song
ISRAEL reveals songs (Eden Alene)
28 February
BELARUS National Final SERBIA Semifinal One
29 February
CROATIA National Final ESTONIA National Final ICELAND National Final 
MOLDOVA National Final PORTUGAL Semifinal Two SWEDEN Andra Chansen SERBIA Semifinal Two
March
RUSSIA reveals song (Little Big)
AZERBAIJAN reveals song (Samira Efendi) MALTA reveals song (Destiny Chukunyere)
1 March
ROMANIA National Final (songs only) SERBIA National Final 
GREECE reveals song (Stefania, "Superg!rl")
3 March
ISRAEL National Final (songs only)
GEORGIA reveals song (Tornike Kipiani, "Take Me As I Am")
4 March
SWITZERLAND reveals artist and song
HOLLAND reveals song (Jeangu Macrooy)
5 March
AUSTRIA reveals song (Vincent Bueno, “Alive”)
IRELAND reveals artist and song
6 March
CYPRUS reveals song (Sandro, "Running")
7 March
DENMARK National Final FINLAND National Final PORTUGAL National Final SWEDEN National Final 
BULGARIA reveals song (Victoria, "Tears Getting Sober")
8 March
MACEDONIA reveals song (Vasil Garvanliev, "You")
9 March
SAN MARINO reveals song (Senhit)
Deadline for entries
Parties
29 March – London Eurovision Party
4 April – Eurovision in Concert, Amsterdam
10-11 April – Eurovision PreParty & Party, Madrid
days until the Eurovision Song Contest Final in Basel!
