Does retroactive prescription between offense and indictment still exist?
Not for offenses from May 6, 2010 onward: Law 12,234/2010 eliminated that specific stretch of retroactive prescription (from offense to indictment). What remains is retroactive prescription between indictment and sentencing, and supervening prescription between sentencing and final judgment, both based on the concrete sentence.
Why can an offense date of February 29 confuse the calculation?
Because February 29 only exists in leap years, and adding years to that date requires deciding what to do when the target year is not a leap year: the correct math rolls forward to March 1, never back to February 28. A calculation that mixes UTC with local-time getters can get that adjustment wrong and return the wrong date.
Does recidivism extend the punitive claim's term?
No. STJ Súmula 220 settled that recidivism does not affect the punitive claim's prescription term, unlike enforcement prescription (PPE), where the 1/3 add-on under art. 110 applies to a repeat offender after the final judgment.