Ideas:

1. In the period Tuesday-Thursday this type of glyph is shorter than in Sunday-Monday and Friday-Saturday. This sign must have another meaning than the cut-off feet, because this shortness does not apply to Friday-Saturday.

2. And we can see that also the rangi-glyph is shorter. Which demonstrates that short is not the same as cut-off. Otherwise we should not have been able to see the short horisontal line defining the lower end of rangi.

3. I guess this shortness could be similar in meaning to the patterns faintly discerned in Large Santiago and Large St Petersburg, where the middle days seem different.