A land sale generated money distributed among four children. Musa received 25%, Amina 30%, Kato half of Amina's share, and Sarah the remaining 120,000,000 shillings. Calculate the total sale amount an

Let $M$ be the total amount of money obtained from the sale of the land.
Musa receives $25\%$ of $M$.
Amina receives $30\%$ of $M$.
Kato receives half of what Amina received, which is $\frac{1}{2} \times 30\% = 15\%$ of $M$.
Sarah receives the remainder, which is 120,000,000 shillings.

Since Sarah received the remainder, her share is $100\% - 70\% = 30\%$ of $M$.

We know that $30\%$ of $M$ is 120,000,000 shillings.

The total amount of money obtained from the sale of the land is $\boxed{\text{400,000,000 shillings}}$.

Musa received $25\%$ of $M$.

Amina received $30\%$ of $M$.

Kato received $15\%$ of $M$.

Musa received $\boxed{\text{100,000,000 shillings}}$, Amina received $\boxed{\text{120,000,000 shillings}}$, and Kato received $\boxed{\text{60,000,000 shillings}}$.

Musa visits every 15 days.
Amina visits every 18 days.
Kato visits every 24 days.
Sarah visits every 30 days.
They all last visited on January 1st.

We need to find the LCM of $15, 18, 24,$ and 30.
Prime factorization:
$15 = 3 \times 5$
$18 = 2 \times 3^2$
$24 = 2^3 \times 3$
$30 = 2 \times 3 \times 5$

The LCM is $2^3 \times 3^2 \times 5 = 8 \times 9 \times 5 = 360$.
So, they will all visit on the same day every 360 days.

Their last common visit was January 1st.
The next common visit will be 360 days after January 1st. Assuming the current year is a leap year (e.g., 2024), February has 29 days.
Counting 360 days from January 1st:
January: 31 days (remaining $360 - 31 = 329$)
February: 29 days (remaining $329 - 29 = 300$)
March: 31 days (remaining $300 - 31 = 269$)
April: 30 days (remaining $269 - 30 = 239$)
May: 31 days (remaining $239 - 31 = 208$)
June: 30 days (remaining $208 - 30 = 178$)
July: 31 days (remaining $178 - 31 = 147$)
August: 31 days (remaining $147 - 31 = 116$)
September: 30 days (remaining $116 - 30 = 86$)
October: 31 days (remaining $86 - 31 = 55$)
November: 30 days (remaining $55 - 30 = 25$)
December: The $25$th day of December.

The next date when all four children will visit their parents on the same day is $\boxed{\text{December 25th}}$.

The parents plan to organize a thanksgiving lunch only if the next common visit falls before the end of March.

The next common visit date is December 25th.
The end of March is March 31st.

Since December 25th is after March 31st, the condition is not met.

The parents should $\boxed{\text{not organize the thanksgiving lunch before the end of March}}$.