Bash program that lists all the years when weekday of your birthday matches your birthday weekday

 

List all years between birthday's year and current one when day of the week matches birthday's day of the week, also lists next year after the last on the list that matches. 

* Uses DATE(1) bash command to do date calculations.

* No other external command required.

Source code: https://github.com/64board/Bash/blob/main/bdates.sh

Python program for calculating office's dates

 mbf_date: A small command-line tool that prints dates based on simple rules.

It can output:

  • the current date
  • the previous date
  • the next date

Optionally, it can treat Saturday and Sunday as non-business days, so:

  • previous business date skips weekends backward
  • next business date skips weekends forward

You can also specify the output format using Python strftime patterns.

Source code:  https://github.com/64board/Python/blob/main/mbf_date.py

 

My First use of ChatGPT

This was my first use of ChatGPT earlier this year: https://chatgpt.com/share/694eca69-8d50-800c-b507-4544ecbd6541

Replacing the seal in a Fluidmaster toilet fill valve is a simple and cost-effective fix if your toilet is running or filling slowly. Here's a step-by-step guide:

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🛠️ Tools & Materials Needed:

• Replacement Fluidmaster seal (usually part #242)

• Towel or small container (to catch water)

• Adjustable wrench (optional)

---

🔧 Step-by-Step Instructions:

1. Turn Off the Water Supply

• Locate the shut-off valve (usually behind or below the toilet).

• Turn it clockwise to stop water flow.

2. Flush the Toilet

• Flush to empty the tank.

• Hold the handle down to get as much water out as possible.

• Use a towel or sponge to soak up any remaining water at the bottom of the tank if needed.

3. Remove the Fill Valve Cap

• The Fluidmaster fill valve cap is usually secured with a twist-lock mechanism.

• Hold the shaft of the fill valve with one hand.

• With the other hand, twist the top cap counterclockwise about 1/8 of a turn and lift it off.

• Some models require gently squeezing side tabs before twisting.

4. Replace the Seal

• Inside the cap, you’ll see a small rubber seal (usually red or black).

• Remove the old seal (you can use a small flathead screwdriver or your fingers).

• Insert the new seal in the same position, making sure it sits flat and centered.

5. Reinstall the Cap

• Line up the cap on top of the valve body.

• Twist it clockwise to lock it back into place.

6. Turn the Water Back On

• Slowly open the shut-off valve.

• Let the tank fill and check for leaks.

• Flush the toilet to ensure proper operation.

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✅ Tips:

• The Fluidmaster 400A is the most common model. Make sure you’re using the right seal for your valve.

• If replacing the seal doesn’t solve the issue, the whole fill valve may need to be replaced (also inexpensive and easy).

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Java Trim

 

When String.trim() “Fails” in Java (And Why It’s Not a Bug)

Every Java developer eventually runs into this head-scratcher:

String s = " hello ";
System.out.println(s.trim());

And yet… the output still looks padded.

At first glance, it feels like trim() is broken.

It isn’t.

What’s broken is the assumption about what trim() actually removes.

Let’s clear this up once and for all.

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What String.trim() Really Does

In Java, String.trim() removes leading and trailing characters whose Unicode code point is ≤ U+0020.

That’s it.

This includes:

• Regular space (U+0020)

• Tabs (\t)

• Newlines (\n)

• Carriage returns (\r)

• A handful of other low-level control characters

If the character’s Unicode value is greater than 0x20, trim() will leave it alone, even if it looks like whitespace.

---

The #1 Reason trim() Appears to Fail

Non-breaking spaces (U+00A0)

This is the usual culprit.

Non-breaking spaces:

• Look exactly like normal spaces

• Commonly appear when copying text from:

  • Web pages

  • PDFs

  • Excel

  • Word documents

• Are not removed by trim()

Example:

String s = "\u00A0hello\u00A0";
System.out.println(s.trim()); // still padded

This isn’t a bug. Java is doing exactly what it’s documented to do.

---

Other Invisible Characters That trim() Won’t Touch

Some especially nasty ones:

• \u00A0 – non-breaking space

• \u200B – zero-width space

• \u2007 – figure space

• \u202F – narrow no-break space

These characters:

• Render invisibly

• Survive trim()

• Can break comparisons, parsing, validation, and logging

---

Common Misunderstandings

❌ “trim removes all whitespace”

Nope. Only specific characters.

❌ “trim cleans the whole string”

Nope. Only leading and trailing characters. Internal whitespace is untouched.

❌ “trim failed, so Java is buggy”

Also nope. This behavior is explicitly defined in the JDK.

---

How to Prove What’s Actually in Your String

When a string refuses to trim, inspect the Unicode values:

for (int i = 0; i < s.length(); i++) {
    System.out.printf(
        "char[%d] = '%c' (U+%04X)%n",
        i, s.charAt(i), (int) s.charAt(i)
    );
}

Once you see U+00A0 or U+200B, the mystery is over.

---

The Right Way to Trim All Whitespace

If your input comes from:

• Files

• Excel

• Web APIs

• Copy-paste

• User input

…then trim() is usually not enough.

Unicode-aware trim using regex

s = s.replaceAll("^\\s+|\\s+$", "");

This handles:

• Standard whitespace

• Unicode whitespace

• Much closer to what people expect “trim” to mean

Aggressive cleanup (separators + control chars)

s = s.replaceAll("^[\\p{Z}\\p{C}]+|[\\p{Z}\\p{C}]+$", "");

Where:

• \p{Z} = Unicode separators (spaces of all kinds)

• \p{C} = control and invisible characters

Use this when dealing with truly messy input.

---

One Last Gotcha: null

Don’t forget:

s.trim(); // throws NullPointerException if s == null

If there’s any chance of nulls, guard it or normalize earlier.

---

Takeaway

String.trim() doesn’t fail.

It just:

• Works exactly as specified

• Assumes you know Unicode

• Is often insufficient for real-world data

If your strings come from outside your JVM, assume they’re dirty—and clean them properly.

If you’ve ever lost time debugging a “trim bug”, now you know: it wasn’t Java.

US Holidays for 2025 and beyond

 I wrote some Excel VBA code to create a list of US Federal holidays.

My GitHub link: https://github.com/64board/ExcelVBA/blob/master/USHolidays.bas