Tooltip for DateTime control is not working in 8.3
The localized Helper text Value(specified by Field Value) is not displaying for Datetime fields. it's expecting field value for pyCaption ,however ,it didn't work with pyActionPrompt,pyLabel,pyCaption & pyToolTip as well .
Seems to be Product bug (https://community.pega.com/support/support-articles/tooltip-datetime-properties-not-working) and it was reported in 7.2 .