**ACTION:**- Convert an interval in days to hours, minutes, seconds
(single precision).
**CALL:**`CALL sla_CD2TF (NDP, DAYS, SIGN, IHMSF)`

**GIVEN:**-

*NDP***I**number of decimal places of seconds *DAYS***R**interval in days

**RETURNED:**-

*SIGN***C**`+' or `-' *IHMSF***I(4)**hours, minutes, seconds, fraction

**NOTES:**- 1.
- NDP less than zero is interpreted as zero.
- 2.
- The largest useful value for NDP is determined by the size of DAYS, the format of REAL floating-point numbers on the target machine, and the risk of overflowing IHMSF(4). For example, on a VAX computer, for DAYS up to 1.0, the available floating-point precision corresponds roughly to NDP=3. This is well below the ultimate limit of NDP=9 set by the capacity of the 32-bit integer IHMSF(4).
- 3.
- The absolute value of DAYS may exceed 1.0. In cases where it does not, it is up to the caller to test for and handle the case where DAYS is very nearly 1.0 and rounds up to 24 hours, by testing for IHMSF(1)=24 and setting IHMSF(1-4) to zero.

Starlink User Note 67

P. T. Wallace

12 October 1999

E-mail:ptw@star.rl.ac.uk