This day is covered in these episodes:
This date is a guess, the events happen sometime early/mid July.
Taking a page out of Ogasawara's playbook, Iguchi starts to dress like the character she's designing and gets to work again. She does the angel exercise with Ema during break times.
It seems like you are visiting this website for the first time (or have cleared your browser cache). This website contains spoilers for the entirety of the anime Shirobako (MAL/ Anilist).
Seriously, the entire show gets practically retold here.
If you are not familiar with Shirobako, please check it out first.
Click the continue button if you are okay with spoilers.