add in half hour measures at rush hour.is this done right??

[nikolai-b]

Sadly not, they need to be integers. Do you want this on Mon-Fri or all days? I've added it in https://github.com/Active-Travel-Academy/ata-traffic-recorder/commit/7f1627754375ed04f219d258c1b35c61497aaba3 for all days but it's easy to change.