Rusty Gun (EP)
21 Achievements
PS4
What month is it?
Find a calendar
75.9%
How to unlock the What month is it? achievement in Rusty Gun - Definitive Guide
BrutalGuitar
TrueAchievements
TrueAchievements
The calendars can be found hidden behind certain walls. Here is a video of one I found in the 5th level in the game. This is after the checkpoint in the level.
Road2unner
The sole hidden collectable of the game is located in the 5th level. Shortly after the mid-level checkpoint you will encounter two shielded enemies. The calendar is in the hidden cave immediately after the second one. Here is an image for visual reference:
Note that the cave does not show up until you jump into it. The trophy will pop soon after. If you miss it during your playthrough you can use chapter select to collect it.