Excel 2021 - Sum cells that contain text for total and total by month

[BrerRabbit]

I'm doing a personal project for gardening. One aspect is that I am calculating the number of eggs laid by my chickens to be summed over time and by month.

I do have this formula: SUM(--RIGHT(D2:H2,LEN(D2:H2)-FIND("= ",D2:H2))). Thing is I don't understand this type of formula, so I'm not sure how to modify it to:
. calculate even if some cells don't have the "= " sign
. to sum for each month. which means look at the date in the first row and extracting the month. I understand that that formula would be =text(D2,"mmmm") for a single cell or column.
. sums will be done on a separate tab with months across the top.

With below, this formula gives a #VALUE response as D2 and E2 don't have the equals sign, even though the answer is 3.

Thank you in advance for your help.

 

[bebo021999]

One way: To add "eggs=0" into all cells
without month
=SUMPRODUCT(SUBSTITUTE(MID(D2:H2&"eggs=0",SEARCH("eggs=",D2:H2&"eggs=0")+5,255),"eggs=0","")+0)
with month criteria
=SUMPRODUCT((MONTH(D1:H1=4)*SUBSTITUTE(MID(D2:H2&"eggs=0",SEARCH("eggs=",D2:H2&"eggs=0")+5,255),"eggs=0","")))

Caculation assistance.xlsx
	D	E	F	G	H
1	07 April 2024	08 April 2024	09 April 2024	10 April 2024	11 April 2024
2	asdad dad	dad blah blah eggs=1	dad blah blah	dad blah blah eggs=2	asdasd
3		3	without month
4		3	with month, with D1:H1 was actual date
Sheet2

Cell Formulas
Range	Formula
E1:H1	E1	=D1+1
E3	E3	=SUMPRODUCT(SUBSTITUTE(MID(D2:H2&"eggs=0",SEARCH("eggs=",D2:H2&"eggs=0")+5,255),"eggs=0","")+0)
E4	E4	=SUMPRODUCT((MONTH(D1:H1=4)*SUBSTITUTE(MID(D2:H2&"eggs=0",SEARCH("eggs=",D2:H2&"eggs=0")+5,255),"eggs=0","")))