CGX uses the same long (4-byte) and short (2-byte) integer formats as GDSII, and the same 8-byte floating point format. These are the only numerical data types defined.
A date is stored as 8 bytes, as shown in the following table. These are the same numerical fields as used in GDSII, though the format is different (bytes are used where possible, rather than shorts). The third column gives the value in terms of the members of the tm structure from the C library.
short | year | tm_year + 1900 |
byte | month | tm_mon + 1 |
byte | day | tm_mday |
byte | hour | tm_hour |
byte | minute | tm_min |
byte | second | tm_sec |
byte | 0 |
As in GDSII, string data are terminated with a null byte, with an additional null byte added if necessary to make the total length even.