Close Manager - Day Label

Hello - Ran into a situation regarding Day Label:

This is for 11.1.2.4 version Close Manager.  The organization does NOT have Day 0 in the close calendar (Day -1 and then Day 1).  Therefore, by changing Day Label in the template and rename Day 0 to Day -1 works on the front end.  User won't see Day 0 in the system

Then, we realized system skip 1 day because day 0 is never been considered in the close calendar nor the template (csv).   System default has Day 0 and we can't remove it.  The workaround we found is shifting one day on the template.  It fixed the problem and re-align the close calendar in CM.  It's counter intuitive when it comes to preparing the template.