(CNN) -- Aviation punctuality reports are a bit like buses; you wait all year for one then two appear at once.
On Thursday, travel data analyst Cirium released its annual On-Time Performance Review, naming Russian flag carrier Aeroflot the world's most on-time global mainline airline and Moscow's Sheremetyevo International Airport the world's most punctual airport.
Then on Friday, rival data analyst OAG unleashed its Punctuality League 2020, declaring Indonesia's flag carrier Garuda Indonesia the world's most punctual airline, Aeroflot the most punctual mega airline in Europe and Sheremetyevo International Airport the world's most punctual mega airport.
So why the discrepancies? What's the difference between a mega airport and a small one? And why is Russia doing so darn well? Join us as we crunch down the results.
The two analysts calculate their results using similar data sources -- Cirium tracks more than 100,000 flights per day, OAG's league is based on 57.5 million flight records using full-year data from 2019 -- but with slightly different categorization. The bigger the airport, the busier the airline, the greater the distances involved, the more challenges to face, and both analysts take this into account when weighing up the performance of airlines and airports.
"Airlines don't always get the credit they deserve for delivering such a complex product," says Cirium in its review.
"Ensuring a seamless customer experience requires vast effort around the clock by a dedicated 'army' of ground staff, flight crew, cabin crew, engineers, ground service agents and many more companies besides within a vast supply chain. They also have to contend with many factors beyond their control, such as inclement weather and air traffic control issues."
It's considerably easier for an airport with fewer than five million departing seats per annum, such as Minsk, the world's top small airport according to OAG, to ensure that 92.6% of its flights depart or arrive within 15 minutes of schedule, than a mega airport handling more than 30 million departing seats.
The excellent performance of mega airport Sheremetyevo, which handles more than 300 flights per day, can in part be attributed to a new third runway adding increased capacity.
Cirium said,"Aeroflot, the largest carrier at the airport maintains nearly 84% of the total operations at SVO. With a carrier owning such a lion's share of operations at one airport, it stands to reason that as Aeroflot goes, so does SVO."
John Grant, senior analyst with OAG, commented in a press release on an impressive year for punctuality. "The global market is reaching near peak [on-time performance].
"The rise [...] is led by Mega Airlines like Aeroflot, Delta and Air France, which are simultaneously expanding the number of operated flights and maintaining high OTP. We're seeing success trickle down to the hubs they service, which benefits the entire travel ecosystem."
The world's most punctual airlines and airports, according to Cirium
Most on-time global mainline airlines:
1. Aeroflot (86.68% of flights on time)
2. All Nippon Airways (86.26%)
3. Delta Air Lines (85.69%)
Most on-time global network airline:
-- LATAM Airlines (86.67%)
Most on-time low-cost carrier:
-- StarFlyer (91.37%)
Breakdown by region:
-- Copa Airlines: No.1 for mainline (92.16% on time) and network (92.27%) operations in Latin America
-- Qatar Airways: No.1 for mainline and network operations (both 82.45%) in the Middle East and Africa
-- Delta Airlines: No. 1 for mainline (85.69%) and network (84.63%) in North America
-- All Nippon Airways: No. 1 for mainline (86.26%) and network (86.49%) in North America
Most on-time airports:
-- Moscow's Sheremetyevo International Airport (SVO) was the most on-time globally and among large-sized airports (95.01%)
-- Taiwan's Kaohsiung International Airport (KHH) was the most on-time medium-sized airport (93.32%)
-- Koh Samui Airport (USM) was the most on-time small airport (95.08%)
The world's most punctual airlines and airports, according to OAG
Top five airlines:
1. Garuda Indonesia (95.01%). World's top mainline airline and top airline in Asia Pacific
2. Copa Airlines (92.01%). Latin America's top airline
3. Skymark Airlines (90.12%). World's top low-cost carrier
4. Hawaiian Airlines (87.4%). North America's top airline
5. LATAM Airlines Group (86.41%). World's top mega airline
Other regional winners:
-- Azerbaijan Airlines (86.81%). Europe's top airline
-- Safair (94.4%). Middle East and Africa's top airline
Most on-time airports:
-- Small airport: Minsk (92.6%)
-- Medium airport: Panama City (92.21%)
-- Large airport: Osaka Itami (88.03%)
-- Major airport: Istanbul Sabiha Gokcen (83.42%)
-- Mega airport: Moscow Sheremetyevo (86.87%)