From 1 November 2026, Turkish citizens need a visa to enter Montenegro. The government adopted the measure on 23 July 2026 as part of aligning its visa policy with that of the European Union (Turkish Minute). The IATA winter season begins one week earlier, on 25 October. Montenegro is one of the main holiday destinations for Turkish citizens, and for airlines in Türkiye a visa decision and a change of schedule season fall in the same week.
That timing raises a planning question: which schedule period offers a valid basis for assessing the effect of the decision? The schedule loaded in airline systems in October is the wrong place to look, and the reason is the transition period.
Under the IATA calendar, summer 2026 runs from 29 March to 24 October, and winter 2026/27 from 25 October to 27 March 2027. By this definition, September and the first three weeks of October formally belong to the summer season. In practice, airlines reduce frequencies and close seasonal destinations in the last weeks of the season. Airline commercial departments call this stretch the transition schedule. Its data represent neither the summer peak nor the winter programme, and conclusions drawn from them deviate in different directions depending on the character of the destination.
Schedules published on flightsfrom.com, an open-access airline data aggregator, show that in Montenegro the deviation runs in both directions. Podgorica to Belgrade, all carriers combined and counted in one direction, has 36 weekly flights in mid-September (14 to 20 September), 45 in early October (5 to 11 October) and 41 in mid-January (18 to 24 January). Two readings taken three weeks apart, both inside the transition period, give opposite answers against the winter schedule. September suggests the route grows in winter. October suggests it shrinks. The transition period is best read as a range that changes from week to week.
At Tivat the contraction is clearer. The week of 5 to 11 October has 122 weekly departures to 22 destinations. In January 2027 the schedule shows 37 weekly departures to 3 destinations. Figures 1 and 2 show the weekly operations of all carriers serving Tivat Airport: the transition schedule (week 41 of 2026, 5 to 11 October) and the winter schedule (week 3 of 2027, 18 to 24 January).
Tivat Airport, all carriers: transition schedule
Week 41 of 2026, 5 to 11 October.
Departures Arrivals. The code in each box is the other end of the flight.
Swipe sideways to see the full day.
Figure 1. Tivat Airport, all carriers, transition schedule: week 41 of 2026 (5 to 11 October), 122 weekly departures.
Tivat Airport, all carriers: winter schedule
Week 3 of 2027, 18 to 24 January.
Departures Arrivals. The code in each box is the other end of the flight.
Swipe sideways to see the full day.
Figure 2. Tivat Airport, all carriers, winter schedule: week 3 of 2027 (18 to 24 January), 37 weekly departures.
Both figures follow the wave schedule view used in schedule planning, with departures above the axis and arrivals below. The airport code in each box shows the other end of the flight (BEG is Belgrade, IST is Istanbul). Data: flightsfrom.com, day-by-day queries; aggregator data, not validated against OAG or Cirium. Independent analysis; wave view built with Claude Code.
The effect of the visa requirement can only be identified against the previous winter schedule period. Montenegro suspended visa-free entry for Turkish citizens on 30 October 2025 (European Western Balkans) and restored it on 23 December 2025, while reducing the maximum stay from 90 to 30 days (European Western Balkans).
Airlines reacted quickly in the winter 2025/26 schedule period. Turkish Airlines had planned three weekly flights to Tivat for the first quarter of 2026. It suspended the route between 12 January and 28 February (EX-YU Aviation) and cut Podgorica from 18 to 14 weekly flights in January (EX-YU Aviation). Pegasus suspended two of its three Podgorica routes, from Ankara and Izmir (EX-YU Aviation).
The winter 2026/27 schedule, as read on 15 September 2026, already reflects part of this experience. Turkish Airlines operates 10 weekly flights between Tivat and Istanbul in the week of 5 to 11 October and shows no Tivat flights in January 2027 (EX-YU Aviation). Pegasus is scheduled to operate 2 weekly flights between Ankara and Podgorica and 3 between Izmir and Podgorica in January.
Winter 2025/26 is the closest precedent, and it carries part of the visa effect. Visa-free entry was suspended in November and December 2025, and the flight cuts in January 2026 followed from that period. A comparison of the two winters therefore understates the effect of the visa. A baseline free of any visa effect would use the winter 2024/25 schedule period.
The visa requirement is one of several regional decisions whose timing coincides with the start of a new schedule period. Serbia prepared rules that would prevent foreign carriers from establishing a base in the country, and Wizz Air argued that these rules are incompatible with the European Common Aviation Area (ECAA) Agreement. On 28 September 2026, Serbia postponed their entry into force to 28 March 2027, the first day of the summer 2027 season (EX-YU Aviation). The decision allows Wizz Air to keep its four-aircraft Belgrade base through the winter. The uncertainty moves to the next season change.
Montenegro's Ministry of Transport has also tendered five public service obligation (PSO) routes from Podgorica, to Brussels, Paris Charles de Gaulle, Frankfurt, Zagreb and Bari. The winning airline commits to operate each route all year, with at least three weekly flights and aircraft of at least 110 seats (EX-YU Aviation). The tender closed on 31 August with Air Montenegro as the only bidder (EX-YU Aviation), and the award had not been announced by the end of September. Planners should note that the published winter schedule may not yet include the flights the tender will bring.
January was chosen as the base week for the winter schedule period instead of November. In leisure markets with seasonal demand, the transition schedule can continue into November, so November weeks do not fully represent the winter programme. The base week was tested against weeks 2 and 4 of 2027, and the same flight pattern appeared in all three weeks.
Schedules published by open-access aggregators change from week to week, so both directions of each route were queried on the same day. Arrival times were calculated from block times (the scheduled gate-to-gate duration of a flight) and time zone differences. Codeshare flights, which one airline sells under another's code, were flagged separately so that frequency counts include each flight once.
Airline commercial departments use decision support systems in schedule planning. These systems assign flights to aircraft within all of the airline's resources and constraints, including the number and capacity of aircraft and the conditions at the airport at the other end of each route. They also produce reports such as wave charts, which show how departures and arrivals cluster through the day, and connection counts by minimum connecting time (MCT), the shortest time a passenger needs to change flights. Outside an airline, these systems and the paid data sources that feed them are out of reach.
AI tools add value to commercial planning when they turn complex analytical processes into code that can be run and repeated. Claude Code was chosen for this work. With reliable data, the logic of the reports produced by decision support systems can be rebuilt in code. Each report was defined with the quantity it measures, the assumptions it uses (such as MCT and maximum waiting time) and the checks it must pass, then built step by step. The result is a dataset of about 6,100 flight records for Belgrade, Podgorica and Tivat, an Excel workbook derived from it, and a wave view for each airport that calculates connections for a chosen MCT and maximum waiting time. Figures 1 and 2 are taken from these views.
The tool carried out instructions quickly. It did not know that a mid-September week does not represent summer, that airlines add buffer time to block times even on the same route, or that a wave has to be read in both directions. Each of these points had to be defined by someone who knew it, and each correction changed the results.
AI makes time productive for those who know how to use it, and in this work, knowing how to use it meant subject expertise. A planner with airline experience recognises a wrong figure in a table at first sight. Without that experience, the same table looks correct, and the tool builds the next table on top of it. The same thread runs through RR CEO's piece on vibe coding, and shapes how the AI automation practice builds.
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About this analysis. Semra Erener has worked with airline schedule planning reports for more than twenty years, in airline senior management and in consulting. This is an independent analysis, and the author has no consulting relationship with any of the airlines named here. Schedule data were collected from flightsfrom.com through day-by-day queries and sit at aggregator level; they have not been validated against a primary schedule source such as OAG or Cirium. The weeks of 14 to 20 September and 18 to 24 January were queried on 15 September 2026, and the week of 5 to 11 October on 2 October 2026. Information on the visa requirement, Serbia, the PSO tender and last winter's schedule changes comes from press reports published between October 2025 and October 2026.
