Why I can not creat the file in SD-card?

[CAP 33]

When I enter echo '123' >> /tmp/mounts/SD-P1/data-$(date +%d.%m.%y-%H:%M:%s).csv
Omega2 write -ash: can't create /tmp/mounts/SD-P1/data-27.12.18-16:49:1545929397.csv: Invalid argument
When I enter echo '123' >> /root/data-$(date +%d.%m.%y-%H:%M:%s)
All working

[György Farkas]

@CAP-33 ":" colon is not allowed character in filename of FAT12, FAT16, FAT32, VFAT, exFAT, NTFS filesystems.
See also Filename

[CAP 33]

@György-Farkas
Thank you