What are the deadlines to send a Pre-lien Notice Letter in Texas?

The dates and deadlines related for lien claims are based off the month and year in which the work was actually performed. The invoice date and company accounting methods are irrelevant in these cases.
Additionally, to qualify to file a lien claim on a property for a commercial project, the subcontractor or supplier, is required to send the invoice or request payment by the 15th day of the second month after the month the work was performed.
A subcontractor who has a direct contract with the General Contractor is called a Tier 1 Subcontractor. The chart below shows the deadline to send Invoices, Pre-lien Notice Letter and Lien Affidavit for private commercial projects for Tier 1 Subcontractors:

FOR CLAIMS RESULTING FROM A CONTRACT SIGNED BEFORE DECEMBER 31ST, 2021
IF THE 15th OF THE MONTH FALLS ON A WEEKEND OR A HOLIDAY, THE LAST DAY TO FILE A VALID LIEN WILL BE THE EARLIEST BUSINESS DAY.

FOR CLAIMS RESULTING FROM A CONTRACT SIGNED AFTER JANUARY 1ST, 2022
IF THE 15th OF THE MONTH FALLS ON A WEEKEND OR A HOLIDAY, THE LAST DAY TO FILE A VALID LIEN WILL EXTEND TO THE NEXT BUSINESS DAY AFTER THAT WEEKEND OR HOLIDAY.