Our information is correct – however, if you are paid monthly, you may have worked during March but not been eligible for furlough.
The payroll is not by February/March – it’s 19th March as long as the employee has had their RTI submission from accounts to HMRC by that date. That means that someone starting in the beginning of March may not be eligible for furlough if they are paid monthly – because RTI submissions are usually completed only a few days prior to payday. The full Government advice is available here: https://www.gov.uk/guidance/check-which-employees-you-can-put-on-furlough-to-use-the-coronavirus-job-retention-scheme
So, you could’ve started on 1st March (or even at the end of February, if your first week’s pay was rolled onto March’s pay) and still not be eligible.
You say you were on the payroll on 16th March; had your RTI been submitted by then, or did you start your job on that date? If the latter, you wouldn’t be eligible (unless the RTI had been submitted prior to 19th March which, if you’re paid monthly, is unlikely). If the former, you ARE eligible for furlough if your employer is choosing to use the scheme.
Originally, the advice was 28th February as the cut-off, but this was revised in March to the 19th March RTI date to reflect the number of people left out of the scheme. (see here: https://www.gov.uk/government/news/furlough-scheme-cut-off-date-extended-to-19-march)
I hope that helps!