The Monthly and Daily Constructs are crucial references in Six Lines (Liu Yao) divination for assessing the vigor and auspiciousness of the lines. The Monthly Construct represents the energy state of the current month, while the Daily Construct reflects the energy state of the day. Together, they form the temporal framework for predictions. Mastering the analysis of these constructs is key to advancing in Six Lines divination.

The Monthly Construct refers to the Heavenly Stem and Earthly Branch of the month in which the hexagram is cast. In Six Lines divination, its influence on the lines is primarily reflected in four aspects: "flourishing, supporting, resting, and imprisoned." A line sharing the same elemental phase as the Monthly Construct is considered "flourishing"; one that generates the Monthly Construct is "supporting"; one generated by the Monthly Construct is "resting"; and one that restrains the Monthly Construct is "imprisoned." Flourishing and supporting lines are strong, while resting and imprisoned lines are weak.

The Daily Construct, also known as the Day Branch, refers to the Heavenly Stem and Earthly Branch of the day the hexagram is cast. Its effect is more direct and specific than that of the Monthly Construct. The Daily Construct can "nurture and support" lines in the hexagram or "clash and restrain" them. Lines sharing the same elemental phase as the Daily Construct are nurtured and strengthened, while those restrained by the Daily Construct are suppressed and weakened.

There is also an interactive relationship between the Monthly and Daily Constructs. The Monthly Construct governs longer-term trends and background conditions, while the Daily Construct represents the immediate state and specific details. For long-term predictions, the Monthly Construct has greater influence; for short-term predictions, the Daily Construct is more significant.

It is important to note that the Monthly and Daily Constructs have a stronger impact on moving lines than on static lines. Moving lines inherently represent change and are more susceptible to external temporal influences. Therefore, when moving lines appear in a prediction, special attention should be paid to the effects of the current month and day.

In practical divination, the analysis of the Monthly and Daily Constructs must be integrated. First, examine the generating or restraining relationship between the Monthly Construct and the focal line to determine the overall trend. Then, assess the specific influence of the Daily Construct on the focal line to gauge the current situation. Finally, synthesize both to arrive at the final judgment of auspiciousness or inauspiciousness. This method is known as the "Integrated Monthly and Daily Analysis."

Analyzing the Monthly and Daily Constructs is one of the most technical aspects of Six Lines divination, requiring a solid foundation in the Five Elements theory and ample practical experience. Beginners are advised to start with simple Monthly Construct analysis, gradually master Daily Construct analysis, and ultimately integrate the two seamlessly.