Whenever I write a fie to a MicroSD card from my Raspberry Pi Pico, if I open the card in a computer the date in something like 05/03/2103 (current date +80 years).
I am sure that the RTC on the Pico is set correctly (i do write a timestamp in the file, and I tested with it connected to a PC with Thonny which syncs it up). This is not a deal breaker, as I said, I do write a timestamp in the file, but it looks strange.

I downloaded the sdcard.py file a couple of days ago from this repository and my Pico is running MicroPython 1.19.
The simplest code that I tried is:

import sdcard
import uos

# Assign chip select (CS) pin (and start it high)
cs = machine.Pin(17, machine.Pin.OUT)

# Intialize SPI peripheral (start with 1 MHz)
spi = machine.SPI(0,
                  baudrate=1000000,
                  polarity=0,
                  phase=0,
                  bits=8,
                  firstbit=machine.SPI.MSB,
                  sck=machine.Pin(18),
                  mosi=machine.Pin(19),
                  miso=machine.Pin(16))

# Initialize SD card
sd = sdcard.SDCard(spi, cs)

# Mount filesystem
vfs = uos.VfsFat(sd)
uos.mount(vfs, "/sd")

try:
    open("/sd/non.txt", "r")
except:
    print ("Non c'è")
else:
    print ("C'è")

# Create a file and write something to it
with open("/sd/test01.txt", "w") as file:
    file.write("Hello, SD World!\r\n")
    file.write("This is a test\r\n")

# Open the file we just created and read from it
with open("/sd/test01.txt", "r") as file:
    data = file.read()
    print(data)```