really cool calendar thing

because there's not enough calendar reform ideas (see XKCD:927)
convert between your system's calendar (probably Gregorian) & really cool calendar dates:
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Features

• It's a Leap week calendar (and thus a Perennial calendar); there are a whole number of weeks in a year. The year always starts on a Monday, and each day of the month is always the same day of the week.
• The leap week cycle follows that of the ISO week date system, an already established and widely-used standard.
  Standard years have 364 days, leap years have 371 days in the form of the Xtraweek (which is still part of December).
• The year always has 13 months of 28 days each (except for December on leap years).
  Sol is the added month, inserted between June and July. It is named "Sol" becuase one of the Solstices takes place during it.
• The years are numbered as in the Holocene year numbering system; effectively just adding 10,000 to the Gregorian calendar year.
  Officially, the numbering is defined such that the year numbered 11970 is the year in which the UNIX Epoch occured.
• The continuous 7-day week cycle is not interrupted; no intercalary days are included. This is done so that religions that worship based on a 7-day cycle continue to always worship on the same day of the week (as opposed to the two cycles drifting out of sync).

Advantages

1. All years & all months have the same arrangement of days, meaning physical calendars and yearly schedules do not expire each year.
2. Each day of the month is always the same day of the week; you don't need to know what year it is to know the 4th is a Thursday
3. All months have the same number of days (save for the one exception for leap weeks in December), no need for weird mnemonics to remember which months are longer or shorter.

Disadvantages

1. The 29th, 30th, and potential 31st days of each month no longer exist, meaning annual events that occur on those dates must be adjusted as appropriate.
2. There is no simple formula for determining whether a given year is a leap year or not.
3. With 13 months (a prime number), the year cannot be evenly divided into whole months.

Counterarguments to the disadvantages (my opinion)

• #2: With the modern advent of computers, most people simply rely on their laptop, phone, or similar device to show them the calendar anyways. Thus, an algorithm that is already implemented in every date-keeping device but is less convenient for mental-math is not a significant downside.
• #3: there are still 52 weeks, so the year can still be easily divided into whole numbers of weeks. Additionally, the week boundary is always Sunday-Monday, so the current half or quarter of the year will never change mid-week.

Other info

• Halloween - October 28th (the last day of October before November)
• New year's eve - December 28th, or December 35th on leap years (the last day of the current year).
• Birthdays - either a nearby date, or the date of the really cool calendar that your birth date occured on.