Sequential Weekday puzzles present statements about yesterday, today, and tomorrow. For example, 'If yesterday was Monday and tomorrow is Wednesday, what day is today?' These problems test your understanding of the sequential nature of weekdays and the ability to deduce the current day from given relationships about adjacent days.

Date Sequence Logic problems provide the weekday of a specific date (e.g., 'January 1st is Monday') and ask for the weekday of another date in the same year. You must calculate the number of days between the two dates and account for the 7-day weekly cycle.

Calendar Grid problems give the first day of a month (e.g., 'The 1st of the month is Monday') and ask for the weekday of another date in the same month. You must calculate the position of the date in the weekly grid, accounting for the starting day.

Month-Day Pair problems involve finding the weekday of a specific date in one month when the weekday of the same date in the previous or next month is known. These problems require calculating the shift caused by the number of days in the intervening month.

February Length problems ask whether February has 28 or 29 days in a given year. You must apply leap year rules to determine if the year is a leap year, which affects not only February but also calculations involving dates around February.

Calendar Cycle Finder problems ask after how many years a given year's calendar repeats exactly (same days for all dates). The cycle depends on whether the year is a leap year and the pattern of weekdays shifting over years.

Multi-Step Calendar Deduction problems involve calculating the weekday of a date when given the weekday of another date, but with multiple steps and possibly different years. These problems require chaining multiple date difference calculations together.

Visual Calendar Grid Reasoning problems present a visual representation of a month's calendar grid (like a typical month view showing dates in rows of weeks). You must answer questions about the grid, such as counting how many times a particular weekday appears, identifying the day of a specific date, or determining the first or last day of the month.

Festival Day Position problems require calculating the date of a movable festival (like Easter Sunday, Diwali, or Thanksgiving) based on calendar rules such as 'first Sunday after the first full moon of spring' or specific lunar calendar positions.

Conditional Weekday Elimination problems use 'if-then' statements about weekdays (e.g., 'If tomorrow is not Tuesday, which day cannot be today?'). You must determine which weekday is impossible given the condition, using logical deduction and weekday relationships.

Historical Calendar Conversion problems involve the transition from the Julian calendar to the Gregorian calendar. In 1582 (and later in different countries), several days were skipped to realign the calendar with the solar year. The most famous example is September 1752 in England, where September 2 was followed by September 14.

Fiscal Calendar Puzzles involve determining the financial quarter (Q1, Q2, Q3, Q4) and semester (Semester 1 or 2) for a given date based on a fiscal year that may start in April (India) or January (many countries). These problems test understanding of fiscal period definitions.

Advanced Odd Days problems involve calculating the total number of odd days over a span of multiple years. Odd days are the remainder when total days are divided by 7. Each normal year contributes 1 odd day (365 mod 7 = 1), each leap year contributes 2 odd days (366 mod 7 = 2). These calculations help determine weekday shifts over long periods.