昭和十八年癸未年辰鬼宿月

[Kiipu]

Nick, Guy, & bangbangsan, this sword tang inscription of 昭和十八年癸未年辰鬼宿月 is giving me problems. I do not understand the meaning of the last four kanji characters. Any ideas what the meaning of this is?
Link to the picture: Akimitsu - Unusual Date Inscription
昭和十八年 = 1943. See Shōwa (1926–1989)
癸未年 = 1943-02-05 to 1944-01-24. See Chinese zodiac
辰鬼宿月 = ????

[Nick Komiya]

鬼宿 is a term from Chinese Astrology for Cancer Ghost (Chinese constellation) - Wikipedia What month that translates into is a little too engaging for my bedtime, sorry.

[Kiipu]

So 辰 is the third lunar month of 癸未年 and 鬼宿 is the 23rd mansion in the 辰 third lunar month? Since there are 28 mansions, would this be the 23rd day in the 3rd month?

辰 = dragon month, in 1943 starts on April 5 and ends on May 3.

[bangbangsan]

If it's 辰月鬼宿日 ，then should be 农历3月23日，1943.4.27 in the Gregorian calendar.

[Kiipu]

Wikipedia states the following under Twenty-Eight Mansions linked to above.

They can be considered as the equivalent to the zodiacal constellations in Western astronomy, though the Twenty-eight Mansions reflect the movement of the Moon through a sidereal month rather than the Sun in a tropical year.

And Wikipedia gives the definition of a sidereal month as follows.

The period of the Moon's orbit as defined with respect to the celestial sphere of apparently fixed stars is known as a sidereal month because it is the time it takes the Moon to return to a similar position among the stars: 27.321661 days (27 d 7 h 43 min 11.6 s). This type of month has been observed among cultures in the Middle East, India, and China in the following way: they divided the sky into 27 or 28 lunar mansions, one for each day of the month, identified by the prominent star(s) in them.

So, 鬼宿 is showing the position of the moon during the 3rd lunar month of 1943. This means it would not match up with a specific day as there are 29 days in the 3rd lunar month. So possibly 鬼宿 should be thought of as an astronomical term rather than as a date?

Wikipedia Search Terms
Twenty-Eight Mansions
Lunar month
Lunar station

[Nick Komiya]

I agree that it says 1943 March 23rd. What is confusing the matter is to read the final character as 月(Month). I don't know what the smith was trying to write, as part of it is obliterated by the hole, but no Japanese will place the two sideways strokes for 月 after a gap like that. As clear in the two kanjis above it, the smith did know how to properly position the start of the side strokes.

[Kiipu]

Unfortunately, there is no picture of the other side of the tang to compare it to. When the army published the manufacturing details for sword blades in April 1942, it stated that blades were to be marked with the date of manufacture. This regulation allowed the use of the sexagenary cycle [干支ニテモ可ナリ]. I guess this swordsmith decided he liked this method better than the other.

[bangbangsan]

I found the answer! It's 1943.4.11. Lunar calendar 3.7.

[Kiipu]

Nick, the other side of the tang can be seen at the link below.
Akimitsu - Unusual Date Inscription

The sword's owner, Tim Blackburne, has posted a 1:35 minute long YouTube video showing the fittings.
WW2 Japanese Type 3 Shin Gunto made by Hiragawa Akimitsu, 1943, Post #16

And finally, Tim extends his thanks to everyone for helping with the date.