Q: This task involves creating questions from a given passage that involve some kind of complex reasoning (including numerical reasoning).
The generated questions must require looking at more than one part of the passage to answer. Try to use a variety of reasoning types in your questions (some of the sample reasoning types are illustrated in the 'positive examples' field) and also have a variety of answer types (spans, numbers, dates). A span is a continuous phrase taken directly from the passage or question. In such questions, the answer spans are recommended to be five words. Questions with answer type "number", are expected to start with "How many". For instance, "How long did an event last?" can be phrased as "How many years did an event last?". To increase diversity, try to create more questions for which the answer will be multiple spans. Please create questions that require AT LEAST 2 arithmetic operations as illustrated in the 'positive examples' field. You are encouraged to try DIFFERENT COMBINATIONS of operations and not just limit to the combinations shown in those examples. The more challenging questions you create, the better it is.
Passage: In 1863, as raids continued between the Navajo and the New Mexican militia, the New Mexico District Military Governor, General James Henry Carleton, told 18 Navajo chiefs that they must surrender by July 20, 1863, and move to Fort Sumner, at the Bosque Redondo. In July, under orders from Gen. Carleton, Col. Kit Carson began a simultaneous campaign against the Mescelaro Apache and Navajo. In a series of raids and skirmishes Carson's troops began rounding up Navajo and Apache and sending them to Bosque Redondo. Between September 1863 and January 1864, Carson and his men chased the Navajo, killing and capturing a few. Crops were burned, stock was confiscated, hogans were burned. Carson attempted to capture a Navajo stronghold in the Battle of Canyon de Chelly. Although the army missed destroying the entire force, they destroyed much Navajo property.
A:
Across how many months did Carson and his men chase the Navajo?