Information from  coshidragonite's journal (found from pixiv).

Today is National Arcanine Day!

I look forward to seeing an influx of Arcanine pictures!

~~~~~

Flareon - 1-10 (January 10)
Magikarp - 1-29 (January 29)
Articuno - 2-03 (February 3)
Pikachu day -2-5 (February 5)
Raichu day - 2-6 (February 6)
Mewtwo - 2-6 (February 6)
Umbreon day - 2-07 (February 7)
Absol - 2-09 (February 9)
Furret - 2-16 (February 16)
Snivy - 2-18 (February 18)
Whimsicott - 2-20 (February 20)
Dratini - 3-2 (March 2)
Corsola - 3-25 (March 25)
Zangoose day - 3-09 (March 9) Reverse Zangoose Day 903 (September 3)
Manectric - 3-10 (March 10)
Oshawott - 3-10 (March 10)
Jolteon day - 3-12 (March 12)
Minun - 3-12 (March 12)
Totodile day - 4-2 (April 2)
Reshiram - 4-06 (April 6)
Shaymin - 4-13 (April 13)
Shelless Wartortle day - (April 14)
Tepig - 4-17 (April 17)
Floatzel - 4-19 (April 19)
Mismagius - 4-29 (April 29)
Buizel Day - 4-30 (April 30)
Dewott - 5-2 (May 2)
Zorua - 5-07 (May 7)
Growlithe day - 5-8 (May 8)
Arcanine day - 5-9 (May 9)
Ducklett - 5-21 (May 21)
Vulpix Day - 6-05 (June 5)
Rotom - 6-16 (June 16)
Leafeon - 6-18 (June 18)
Jirachi - 7-7 (July 7)
Butterfree - 8-2 (August 2)
Trubbish - 8-2 (August 2)
Pachirisu - 8-8 (August 8)
Beautifly - 8-10 (August 10)
Aipom - 8-6 (August 6) *not sure*
Dragonair - 8-9 (August 9)
Typhlosion - 8-9 (August 9)
Espeon Day - 8-21 (August 21)
Joltik - 8-26 (August 26)
Glaceon - 9-1 (September 1)
Wooper - 9-4 (September 4)
Quilava - 9-4 (September 4)
Ninetales - 9-5 (September 5)
Zekrom - 9-06 (September 6)
Mightyena - 9-7 (September 7)
Pichu Day - 10-2 (October 2)
Chikorita - 10-5 (October 5) *not sure*
Timburr - 10-25 (October 25)
Ampharos - 11-1 (November 1)
Eevee Day - 11-21 (November 21)
Bulbasaur Day - 11-24 (November 24)