Sacred holidays are designed to be peaks of spiritual connection and national celebration. However, when a nation abandons its spiritual compass, these very moments of joy are destined to transform into periods of profound darkness and distress. The complete end of the nation's happiness is brought about by an overwhelming wave of troubles. In the past, these special days were marked by rest and the offering of additional sacrifices, but the impending hardships will make any natural sense of joy impossible [רד״ק]. This represents a sudden and absolute end to their national celebrations [מצודת ציון, ביאור שטיינזלץ].
There are two primary reasons for this harsh consequence. One perspective is that the people corrupted their holidays by dedicating them to idolatry. They falsely believed that their success during these times was dictated by the stars and constellations. In response, God plunges their joyous days into darkness to clearly prove that He alone controls time and the heavens [מלבי״ם]. Another perspective suggests that the people attempted a compromised religious life, blending the worship of God with the worship of local idols. They observed the sacred gatherings merely to serve their own physical pleasures. Because of this self-serving approach, the protective merit of observing the Sabbaths and holidays is stripped away, signaling that the protective merit of their ancestors has also run out for that generation [אברבנאל].
The disruption of joy spans the entire sacred calendar. This includes the New Moon, a time of lunar renewal traditionally celebrated as a day of happiness [אבן עזרא, רד״ק, ביאור שטיינזלץ]. A conceptual distinction exists between the different types of sacred gatherings affected by this decree. The primary approach among commentators is that the festivals refer specifically to the three main pilgrimage holidays, while the appointed times include other holy days like the New Year, the Day of Atonement, and the Eighth Day of Assembly [רד ק בשם רב סעדיה גאון, מצודת דוד]. Pilgrimage holidays are characterized by specific peace offerings, festive meals, and joyful gatherings. In contrast, the appointed times are defined strictly by their fixed, predetermined dates on the calendar, even if they do not involve festive meals or specific holiday sacrifices, as is the case with the New Year and the Day of Atonement [מלבי״ם, רד״ק].