Do It Today in Chinese / Japanese...

今日事今日畢 is a Chinese proverb that means “never put off until tomorrow what you can do today.”

活在今天 is not an eastern concept, so it does not translate into a phrase that seems natural on a wall scroll.

However, if this is your philosophy, the characters shown here do capture your idea of living for today or living in the moment. 活在今天 says “Live in today,” and they are grammatically correct in Chinese.

Note: This kind of makes sense in Korean Hanja but the grammar is Chinese, so it’s not that natural in Korean.

These are the five principles of Reiki.

They translate into English as...

At least for today:
Do not be angry,
Do not worry,
Be grateful,
Work with diligence,
Be kind to people.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.

靈氣療法肇祖臼井甕男先生遺訓招福の秘法萬病の霊薬今日丈けは心配すな感謝して業を励げめ人に親切に is an alternate version of the precepts or tenets of Reiki by Usui Mikao.

It is impossible to be sure which version or versions were actually written by Usui Mikao. This is the less common of the three versions that you might see in the wild.

Here is a breakdown of the characters and a rough translation:
靈氣 療法 肇祖 臼井甕男。
Reiki therapy founder Mikao Usui
先生 遺訓。
Teacher's testament 招福の秘法,　萬病の霊薬。
Invite blessings of [the] secret method, 10,000 illnesses of spiritual medicine.
今日丈けは: 怒るな, 心配すな,　感謝して,　業をはげめ,　人に親切に。
At least for today: Do not be angry, do not worry, be grateful, work with diligence, [and] be kind to people.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.

These are the precepts of Reiki that are attributed to Usui Mikao.

Here is a breakdown of the characters and a rough translation:
招福の秘法,　萬病の霊薬。
Invite blessings of [the] secret method, 10,000 illnesses of spiritual medicine.
今日丈けは:　怒るな,　心配すな,　感謝して,　業をはげめ,　人に親切に。
At least for today: Do not be angry, do not worry, be grateful, work with diligence, and be kind to people.
朝夕合掌して,　心に念じ,　口に唱へよ,　心身改善。
Morning [and] evening perform gassho (join hands), [with your] heart/mind in silent prayer, [with your] mouth chant, [thusly] mind [and] body [will] reform/improve.
臼井靈氣療法！　-肇祖,　臼井甕男。
Usui Reiki Ryōhō! -Founder, Usui Mikao.

The middle portion of this is often titled, “The Five Principles of Reiki” and makes a nice calligraphy selection by itself. The Japanese text presented here can be considered the more verbose version.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.

Hapkido or 合氣道 is a mostly-defensive martial art in Korea.

Hapkido has some connection to the Aikido of Japan. They are written with the same characters in both languages. However, it should be noted that the Korean Hanja characters shown here are the traditional Chinese form - but in modern Japan, the middle character was slightly simplified.
Note: You can consider this to be the older Japanese written form of Aikido. Titles on older books and signs about Aikido use this form.

The connection between Japanese Aikido and Korean Hapkido is muddled in history. The issue is probably due to the difficult relationship between the two countries around WWII. Many Koreans became virtual slaves to the Japanese during that period. After WWII, many things in Korea were disassociated from having any Japanese origin. The relationship has greatly mellowed out now.

Looking at the characters, the first means “union” or “harmony.”
The second character means “universal energy” or “spirit.”
The third means “way” or “method.”
One way to translate this into English is the “Harmonizing Energy Method.” This makes sense, as Hapkido has more to do with redirecting energy than fighting strength against strength.

More Hapkido info

More notes:
1. Sometimes Hapkido is Romanized as “hap ki do,” “hapki-do” “hab gi do” or “hapgido.”

2. Korean Hanja characters are actually Chinese characters that usually hold the same meaning in both languages. There was a time when these characters were the standard and only written form of Korean. The development of modern Korean Hangul characters is a somewhat recent event in the greater scope of history. There was a time when Chinese characters were the written form of many languages in places known in modern times as North Korea, South Korea, Japan, Vietnam, Singapore, Hong Kong, Taiwan, Mainland China, and a significant portion of Malaysia. Even today, more people in the world can read Chinese characters than English.

3. While these Korean Hanja characters can be pronounced in Chinese, this word is not well-known in China and is not considered part of the Chinese lexicon.

Long ago in what is now China, there were many kingdoms throughout the land. This time period is known as “The Warring States Period” by historians because these kingdoms often did not get along with each other.

Sometime around 279 B.C. the Kingdom of Chu was a large but not particularly powerful kingdom. Part of the reason it lacked power was the fact that the King was surrounded by “yes men” who told him only what he wanted to hear. Many of the King's court officials were corrupt and incompetent which did not help the situation.

The King was not blameless himself, as he started spending much of his time being entertained by his many concubines.

One of the King's ministers, Zhuang Xin, saw problems on the horizon for the Kingdom, and warned the King, “Your Majesty, you are surrounded by people who tell you what you want to hear. They tell you things to make you happy and cause you to ignore important state affairs. If this is allowed to continue, the Kingdom of Chu will surely perish, and fall into ruins.”

This enraged the King who scolded Zhuang Xin for insulting the country and accused him of trying to create resentment among the people. Zhuang Xin explained, “I dare not curse the Kingdom of Chu but I feel that we face great danger in the future because of the current situation.” The King was simply not impressed with Zhuang Xin's words.
Seeing the King's displeasure with him and the King's fondness for his court of corrupt officials, Zhuang Xin asked permission from the King that he may take leave of the Kingdom of Chu, and travel to the State of Zhao to live. The King agreed, and Zhuang Xin left the Kingdom of Chu, perhaps forever.

Five months later, troops from the neighboring Kingdom of Qin invaded Chu, taking a huge tract of land. The King of Chu went into exile, and it appeared that soon, the Kingdom of Chu would no longer exist.

The King of Chu remembered the words of Zhuang Xin and sent some of his men to find him. Immediately, Zhuang Xin returned to meet the King. The first question asked by the King was “What can I do now?”

Zhuang Xin told the King this story:

A shepherd woke one morning to find a sheep missing. Looking at the pen saw a hole in the fence where a wolf had come through to steal one of his sheep. His friends told him that he had best fix the hole at once. But the Shepherd thought since the sheep is already gone, there is no use fixing the hole.
The next morning, another sheep was missing. And the Shepherd realized that he must mend the fence at once. Zhuang Xin then went on to make suggestions about what could be done to reclaim the land lost to the Kingdom of Qin, and reclaim the former glory and integrity of the Kingdom of Chu.

The Chinese idiom shown above came from this reply from Zhuang Xin to the King of Chu almost 2,300 years ago.
It translates roughly into English as...
“Even if you have lost some sheep, it's never too late to mend the fence.”

This proverb, 亡羊补牢犹未为晚, is often used in modern China when suggesting in a hopeful way that someone change their ways, or fix something in their life. It might be used to suggest fixing a marriage, quitting smoking, or getting back on track after taking an unfortunate path in life among other things one might fix in their life.

I suppose in the same way that we might say, “Today is the first day of the rest of your life” in our western cultures to suggest that you can always start anew.

Note: This does have Korean pronunciation but is not a well-known proverb in Korean (only Koreans familiar with ancient Chinese history would know it). Best if your audience is Chinese.