Probably it's possible, you have to dive in the Calendar's js.
The calendar already has a parameter called 'Align'. See it's description:
"
A 2-characters string used to set the vertical & horizontal alignment of the calendar.
The first character is the vertical alignment and can take one of the following values:
T - completely above the reference element (bottom margin of the calendar aligned to the top margin of the element).
t - above the element but may overlap it (bottom margin of the calendar aligned to the bottom margin of the element).
c - the calendar displays vertically centered to the reference element. It might overlap it (that depends on the horizontal alignment).
b - below the element but may overlap it (top margin of the calendar aligned to the top margin of the element).
B - completely below the element (top margin of the calendar aligned to the bottom margin of the element).
The second character is the horizontal alignment and can take one of the following values:
L - completely to the left of the reference element (right margin of the calendar aligned to the left margin of the element).
l - to the left of the element but may overlap it (left margin of the calendar aligned to the left margin of the element).
c - horizontally centered to the element. Might overlap it, depending on the vertical alignment.
r - to the right of the element but may overlap it (right margin of the calendar aligned to the right margin of the element).
R - completely to the right of the element (left margin of the calendar aligned to the right margin of the element)."
The default vertical alignment option is 'b'. Probably the best way is to add a 'auto' option, and apply this method to it.