feat(timeutil): output proper RFC3339 format for atom

Previously, since we used strftime %z it'd output an offset as +HHMM
while RFC3339 requires +HH:MM. Currently we implement outputting this
manually which proved to be non-trivial because of the tzset() API.
This probably should be improved in the future since I suspect it
produces incorrect results in some edge cases.

1 files changed, 25 insertions, 0 deletions

diff --git a/bitutil.c b/bitutil.c
new file mode 100644
index 0000000..8b2807f
--- /dev/null
+++ b/bitutil.c
@@ -0,0 +1,25 @@
+char nibble_hex(short h) {
+    switch(h) {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+        case 5:
+        case 6:
+        case 7:
+        case 8:
+        case 9:
+            return (h + 48);
+        case 10:
+        case 11:
+        case 12:
+        case 13:
+        case 14:
+        case 15:
+            return (h + 55);
+        default:
+            return 0;
+    }
+}
+