Delay in my salary payment

[jimmymcad]

HI,

Due to some payroll problem, i got my March and April salary delayed and got it after 18 days and 6 days than the normal time. Should i get a letter from my employer, indicating the cause of delay for extending my hsmp visa to Tier1,
Though it is deposited after 18 days and 8 days respectively, and my bank statement shows it.
Will it be a problem in my extension?

Please let me know, what should be the exact content if i ask for the letter? OR i do not need that letter from my employer.
If yes do i need separate letter for each month
Please suggest

Many thanks