Yeah, the standard CSS classifyers won’t work as they are identical across the buttons, but they each have a different aria label for accessibility, which can be leveraged:
.button-wrap aaria-label='Calendar'] {
display: none;
}
Just be aware, while technically there is nothing wrong with this, its not the intention of the aria label, and aria labels can be updated more often as the impact to things like CSS is generally not a concern like updating other classes or ID’s. That being said, this one being ‘Calendar’ seems fairly safe.