DNA is analogous to computer languages, which are formal but not declarative: their texts consist of instructions that have no truth values, nor does the whole text have a truth value (the assessment of computer program as "correct" is external, computer needs none of that to execute it). DNA is similarly a sequence of instructions for producing a specimen, and it does have an alphabet and composition rules. Time intervals are not specified because there is no point to do so, execution time depends on "hardware" and environment, will differ depending on it, often can not be controlled, and therefore has to be irrelevant. In other words, instructions must work when executed in sequence regardless of the execution time.
Of course, some instructions may be time sensitive, and some computer languages that work with real time applications do have means to constrain execution time. For example, if your browser can not establish connection with a server for prescribed period of time it will abort, and display the message like "connection timed out". Epigenetic mechanisms may perform some such functions for DNA.