This bit works

if year('Date & Time') < 2017 then
'Miles Travelled' - 20
else
'Miles Travelled' - 10
end

I can't get anothe IF in there though...

Why doesn't this work?

if timestamp('Date & Time') < 1483228800 then
'Miles Travelled' - 22;
if timestamp('Date & Time') < 1522537200 then
'Miles Travelled' - 32
else
'Miles Travelled' - 20
end
end

(1483228800 is the unix timestamp for 01-01-2017)

Am I trying to do the impossible?

Thanks. The missing 'else' dosn't help me. The two if statements fail and I end up with the final calculation.

For a record dated in 2016, the first if should find a date before 01-01-2017 in 'Date & Time' and subtract 22 from 'Miles Travelled'. It doesn't, it just moves through to the final else.

I can make

if year('Date & Time') < 2017 then

work but I can't find a month and year if I try

if yearmonth('Date & Time') < 2016/04 then

Will a switch help?!

Here's the answer!

My tme stamps were short. I got the stamp for 01-01-2017 from https://www.unixtimestamp.com and it returned 1483228800.

The stamps from Ninox are longer by three zeros. Once I used 1483228800000 in the condition all was well.

Phew!