ALBANY - Hoping to cast your primary ballot Thursday before dropping the kids off at school or heading into work?

Better check when the polls open in your county.

Thursday's state and local primary elections again highlight New York's often-criticized law requiring some counties to open their polls before others.

It means voters in Buffalo or New York City can cast their ballot first thing in the morning while those in Rochester or Binghamton will have to wait until noon.

Wondering when the polls open where you live? Read on.

When do primary polls open in New York?

It depends where you live.

The polls open at 6 a.m. Thursday if you live in New York City, on Long Island or in the following counties: Westchester, Rockland, Putnam, Dutchess, Orange or Erie.

The polls open at noon Thursday If you live in one of the 49 other counties in the state, including Monroe, Broome, Tompkins and Chemung.

A reminder: The primary elections Thursday are only for state and local offices. The congressional primaries were in June.

When do the primary polls close?

That's an easy one: 9 p.m., no matter where you live in the state.

Why does it vary from county to county?

Because that's what the law says.

New York election law specifies exactly when polling places in the state are to open and close.

For the general election, it's uniform: 6 a.m. to 9 p.m. across the entire state.

For primaries, it's laid out by county.

Specifically, it's in Section 8-100 (2) of the state Election Law:

"Polls shall be open for voting during the following hours: a primary election from twelve o’clock noon until nine o’clock in the evening, except in the city of New York and the counties of Nassau, Suffolk, Westchester, Rockland, Orange, Putnam, Dutchess and Erie, and in such city or county from six o’clock in the morning until nine o’clock in the evening."

The polling hours law dates back to 1909, when it required all counties outside New York City to open their polls from noon to 9 p.m., according to the state Board of Elections. The city's polls, meanwhile, were open from 3 p.m. to 10 p.m.

It stayed that way for the next six-plus decades.

In 1973, the law was changed to require New York City to open polls from 6 a.m. to 9 p.m. Slowly over the years, other counties were added to the list — including this year, when Dutchess will start opening up at 6 a.m.

Then-Albany Mayor Erastus Corning and Monroe County challenged the non-uniform voting hours in 1982, arguing that it disenfranchised upstate voters. But the Court of Appeals upheld the system, ruling that it didn't prevent people from voting and that the state Legislature could set voting hours.

Has the split system caused issues?

It has — particularly when it comes to high-profile elections like the 2016 presidential primary.

In a December 2016 report on voter issues during the presidential elections, then-Attorney General Eric Schneiderman's office said it received numerous complaints from upstate voters who headed to the polls in the morning only to be turned away.

A voter in Schuyler County, for example, contacted Schneiderman's office to say she arranged for a home health aide to take care of her ailing, 91-year-old mother so she could cast a ballot in the morning.

When she got to the polling place, she realized it didn't open until noon, according to the report.

"Uniformity amongst counties in poll hours would create a fairer election system and, as a practical matter, decrease voter confusion as to poll hours," Schneiderman's office wrote.

Will it ever change?

The state's primary voting hours have long drawn criticism from good-government organizations and voters in the noon-opening counties, but the law remains on the books.

One reason why: It would cost the counties money to open their polls an extra six hours.

"They will come back and say, 'Well, it costs more money,'" said Assembly Elections Committee Chair Sandra Galef, D-Ossining, Westchester County.

"Well, being in a democracy does cost some money and the current system disenfranchises upstate voters."

Galef and Syracuse-area Sen. David Valesky sponsor a bill that would require all counties to open their primary polls at 6 a.m.

The Legislature ended its annual legislative session this year without putting it to a vote.

JCampbell1@Gannett.com

Jon Campbell is a correspondent with USA TODAY Network's Albany Bureau.