For ⽈, Wictionary  suggests the same pronunciations and meanings, as for 曰 X66F0: 曰（エツ、ひらび、いわく） (etsu, hirabi, iwaku) and no specific meaning. Perhaps, it fall under the press of censorship and denotes something tabooed.
The four Unicode characters look similar at the screen.
Even a native Japanese speaker, looking at characters
⽇, ⽈, 日, 曰
is unlikely to answer:
Which of them is KanjiRadical X2F47?
Which of them is KanjiRadical X2F48?
Which of them is KanjiLiberal X65E5?
Which of them is KanjiLiberal X66F0?
php ud.t 2F47 2F48 65E5 66F0
reveals the encoding:
2F47 12103 ⽇ ⽇
Unicode character number 12103 id est, X2F47
Picture: ⽇ ; uses 3 bytes. These bytes are:
XE2 XBD X87 in the hexadecimal representation and
226 189 135 in the decimal representation
2F48 12104 ⽈ ⽈
Unicode character number 12104 id est, X2F48
Picture: ⽈ ; uses 3 bytes. These bytes are:
XE2 XBD X88 in the hexadecimal representation and
226 189 136 in the decimal representation
65E5 26085 日 日
Unicode character number 26085 id est, X65E5
Picture: 日 ; uses 3 bytes. These bytes are:
XE6 X97 XA5 in the hexadecimal representation and
230 151 165 in the decimal representation
66F0 26352 曰 曰
Unicode character number 26352 id est, X66F0
Picture: 曰 ; uses 3 bytes. These bytes are:
XE6 X9B XB0 in the hexadecimal representation and
230 155 176 in the decimal representation
php du.t ⽇⽈日曰
Test for the good vision
Then, at some software, 日 (日 X65E5)
appears a little bit slimmer than 曰 (曰 X66F0).
In addition, at some software, in the image of nichi (曰 X66F0), the central horizontal stick at right hand side does not touch the right hand side vertical stick. Is the character is shown with black on white, then, there is at least one white pixel between the central horizontal stick and the right hand side vertical stick. This white pixel can be seen at the strong zooming-in of the character. If the characters are enlarged to half-screen each, the difference can be seen without microscope.
In Wictionary article about 曰 (曰 X66F0), this is expressed with sentence Not to be confused with 日, which is generally slimmer and taller, and has a middle stroke that often extends to both sides in non-regular script fonts.
Such a method could be useful in a Motor Vehicle Division for the visual test; the drivers with good vision are supposed to be able to distinguish the printed version of character 曰 from the printed version of character 日.
For the Human applications, it has sense to indicate the hexadecimal encoding after any character, qualified as nichi. Then, he resolving become easy and straightforward:
X65E5 is 日;
X66F0 is 曰
; this can be seen even without to zoom-in the character.
- https://ja.wiktionary.org/wiki/%E2%BD%88 https://ja.wiktionary.org/wiki/⽈ 部首 フリー百科事典ウィキペディアに 曰部 の記事があります。 曰（エツ、ひらび、いわく） 漢字の部首の一つ。発話に関する意味の漢字を表し、曰部を構成。常用漢字では四画。 参照 Wiktionary:漢字索引 部首 曰。
- https://util.unicode.org/UnicodeJsps/character.jsp?a=2F47 ⽇ 2F47 KANGXI RADICAL SUN Han Script id: allowed confuse: 日
- https://util.unicode.org/UnicodeJsps/character.jsp?a=2F48 ⽈ 2F48 KANGXI RADICAL SAY Han Script id: allowed confuse: 曰
- https://util.unicode.org/UnicodeJsps/character.jsp?a=65E5 日 65E5 CJK UNIFIED IDEOGRAPH-65E5 Han Script id: restricted confuse: ⽇
- https://util.unicode.org/UnicodeJsps/character.jsp?a=66F0 曰 66F0 CJK UNIFIED IDEOGRAPH-66F0 Han Script id: restricted confuse: ⽈
- https://en.wiktionary.org/w/index.php?title=⽈&redirect=no Redirect 曰
- https://en.wiktionary.org/wiki/曰 曰 (radical 73, 曰+0, 4 strokes, cangjie input 日 (A) or X日 (XA), four-corner 60100, composition ⿴囗一) Kangxi radical #73, ⽈.